40D vs 1D MkIII for BIF

[Tim Dodd]

Hi Tim. I'll speak again from the technical side.

Roger

I appreciate your thorough technical analysis of these things. I sent you several dark frame raw files from my 50D when it first came out, in order to assist you in your research. I fear that within this thread we have become drawn a bit too deeply into technicalities.

Initially the only point I wanted to make is that if one is fastidious enough to be concerned about ETTR when shooting raw, one might also want to be aware of just how HTP operates and how it is undermining the very objective you have in mind. For that specific reason it is not logical to leave HTP enabled by default. Perhaps we can just leave things there.

[Leonard Malkin]

[QUOTE=Jay Gould;235765]Artie, unfortunately some of us are very linear and also unfortunately need it spelled out.

You wrote, and have written numerous times:

"For most flight photography, using only the central sensor is best. The latest blog post deals with when to use AAFPS for flight photography: http://www.birdsasart-blog.com/"

Roger, on his website in a wonderful description of Autofocus wrote:

"Use one focus point: A common mistake in action shots is to use multiple Auto Focus (AF) points, then the camera confuses the subject and often locks on to something you don't want. Use one focus point and keep that AF point on the moving subject so the AI servo can track it. The AF system has trouble with contrasty back lit subjects, so try and choose well lit subjects and/or backgrounds that are smooth (like birds with blue sky background). " http://www.clarkvision.com/photoinfo...cus/index.html

Leonard, as an aside, trust me (;)), buy Artie's BAA1 and BAA 2, and study Roger's website.

Continuing,

Artie, you wrote on the blog:

"When attempting to photograph erratic flight or action, I will often choose AAFPS, All AutoFocus Points Selected as in most cases this make it easier to track the bird or to maintain focus on two birds that are interacting."

I will wear the dunce cap: please expand the differences between "flight" and "erratic flight or action" so that us dunces will have some idea when to use a single sensor and when to use AAFPS.

Everyone else can jump in regarding this distinction too!

In addition, Artie states in a heading for a photo on page 735 in "Art of Bird Photography II" and I quote - "When I was younger I was able to do flight with the central sensor but now I generally rely on 45-point AFPS". This brings me back to my former thought that perhaps I am just too old (72) to rely on reflexes to track BIF with the central sensor.

Now, if old Artie relies on the AFPS, and if Canon is correct in stating that a subject will stay in focus if covered by one of the focus points, does this not follow that 45 points is better than 9 and that AFPS on a 1D MkIII would be better for me?

[Leonard Malkin]

Also, I'm sure operator error is a problem although I wouldn't call it an error, it's just that at my age (72) I'm just not fast enough to keep the fast fliers in place.

I am 62 and I am in the same boat. I ain't as fast as I used t be. The great news is that I am still breathing.


Artie, since one of my problems is simply trying to track BIF hand-held, do you think a gimbal or ball head on a tripod would allow for more accurate tracking?

[Leonard Malkin]

[QUOTE=Doug Brown;235940]There's a lot of misinformation floating around the internet on the 50D. Don't mistake group-think for fact. Just because Canon doesn't advertise the fact that AF is improved on the 50D doesn't mean that it hasn't been improved.

Why wouldn't Canon advertise that AF is improved on the 50D?

[Axel Hildebrandt]

[quote=Leonard Malkin;237922]

I will wear the dunce cap: please expand the differences between "flight" and "erratic flight or action" so that us dunces will have some idea when to use a single sensor and when to use AAFPS.

Everyone else can jump in regarding this distinction too!

Leonard, there are birds that have very predictable flight patterns such as herons while swallows and buntings can fly quite erratically and this is when using more than the central focus point can help, at least if the BG is not tricking the AF system.

[Jay Gould]

Hi all, Roger made an interesting statement that has caused me to continue this discussion, but first.........

See this extract from a guide to using the 1D3 AF system....

Tim, no link provided.

While not understanding all of this even close to the technical level of Tim and Roger, and also not willing to simply turn on HTP as a full time default since I do shoot in Raw, and since I am new to the game and want to understand what I am doing so that I do it "right" from the outset, ...

I believe in the saying "do it right; do it once"

... Roger, you said:

I think you are trying to split too many hairs even though technically you are right.

"Splitting hairs", I accept that to be the case because you, Roger, say it is so and clearly you are a techie's techie! However, the newbie (ME and others) without all of the Artie's experience that can overcome a lot of minor technical differences, says to you and other technical persons

OK, what is our default setting when shooting RAW? Even if it is splitting hairs, even if Artie uses HTP with RAW because he is an expert and his images do not suck :D and he has never thought to do otherwise , when you are writing standard settings for a camera that a newbie is going to rely on,

should HTP be turned on or off as a default when shooting RAW?

And, if off as the default when shooting RAW, when do you turn it on, if at all, when shooting RAW.

Photographers like Artie have so many years of experience and they have been doing it a certain way and refining that way over the years that as a result they obtain brilliant images.

Photographers like Roger know, understand, and apply the technical side to their cameras and obtain brilliant images.

Please, while debating the technical do not overlook that probably most of the members of BPN are neither technical like Roger and Tim, nor have the years of experience under their belts as do Artie and others.

We come to the forum like sponges and read everything we can. We read from Artie to turn on HTP as a default and we do so until along comes Tim and says - "wait a minute" that doesn't make tecnical sense. Then along comes Roger and says "Tim you are splitting hairs although you are technically right".

What happens is photographers like myself trying to learn go "whoa, back up, the techies are saying to turn off HTP. Hmmm, I wonder if I turn off HTP whether that will help me achieve better IQ quicker than the years Artie has expended, while still realizing that we have to get out there and shoot and shoot?

So, techies: shooting RAW - HTP on or off and if off when do we turn it on; if on do we ever turn it off?

Sorry for the rambling; I simply feel that the persons like myself trying to learn from both the wisdom of experience and the technical knowledge of the techies gets overlooked in the debate. While we do not need to know how the camera runs in every little technical detail, we do need to know what buttons to push or not to push if it is going to make a difference.

;) :D

[Roger Clark]

So, techies: shooting RAW - HTP on or off and if off when do we turn it on; if on do we ever turn it off?

Hi Jay,

Sometimes knowing the technical detail of how a camera works can make a real difference in its use. Other times, and this is just my opinion, the differences are so small that other things can be more important.

Tim is 100% correct about HTP: it underexposes by a stop in order to preserve highlights then applies a different tone curve and in the process noise in shadows is higher. But with that one stop the noise is not that much worse. So it is my opinion that if you are in situations where you could benefit from HTP go ahead and use it, knowing that technically, shadow noise is only about 40% worse so not a big deal. Actually thinking about it, noise should also be higher at all levels. If HTP is underexposing a stop, that would be the case. In the field I am often doing exposure compensation of 1/2 to 2/3 stops, so its not that much different.

In photographing birds in flight, lighting can change rapidly with your changing angles, metering can be difficult. But for us less experienced than the pros who have shot hundreds of thousands of BIF, we are more challenged by all the things we must be constantly aware of, the least of which is 40% more noise in the shadows or rest of the image. When I'm not chained to my computer and do get out to photograph, I'm more concerned about my tracking performance, do I have the composition and AF point the way I want it, is my shutter speed high enough, should I be doing manual metering, etc. 40% more noise is not in my top ten, maybe not even my top 20. So that is why a said it was splitting hairs.

I personally do not use HTP, but that is mainly because I still use a 1D Mark II that doesn't have it, and I want to use each camera similarly. I still use the old fashion way of deciding when I need exposure compensation and apply it when I feel I need it. But for those who do use it, that is fine. I probably personally wouldn't set it permanently though once all my cameras have it. But that is because I generally opt for the minimum settings, more of the I want to control things my way attitude. But that is just me.

Roger

[Jay Gould]

Thanks Roger, the default will now be HTP OFF.

if you are in situations where you could benefit from HTP go ahead and use it

How about a brief nontechnical, if possible, description about the situations when you can benefit from HTP?

[Tim Dodd]

Hi all, Roger made an interesting statement that has caused me to continue this discussion, but first.........

Tim, no link provided.

Sorry, there should be a couple of JPEG screen captures from a document I have about optimising AF settings for thr 1D3 and 1Ds3. I don't understand why they are not showing. If you look at tview on this page - http://www.the-digital-picture.com/R...ra-Review.aspx - hopefully you will get a better sense of what the 1 series AF system offers.

[Tim Dodd]

How about a brief nontechnical, if possible, description about the situations when you can benefit from HTP?

OK, I'll try, but I'm not sure if I'll be brief.

Firstly I suggest that if you do not understand the significance of "Expose To The Right" technique for shooting raw it would first be worth coming up to speed on that topic. This has little/nothing to do with HTP per se, it is simply one good practice that can be employed to maximise image quality. Before refreshing our minds on that topic it is also worth remembering that when you shoot to raw your purpose is to capture "DATA" from which you can then craft the finest image possible to suit your creative desires. This is quite different from shooting to JPEG, when you ideally want to have everything set perfectly within the camera. The camera is performing your post processing for you to create the "final" JPEG result. Anyway, ETTR refreshers....

http://www.luminous-landscape.com/tu...se-right.shtml

http://ronbigelow.com/articles/exposure/exposure.htm

So now, hopefully, we can understand the goals and objectives that make ETTR a worthwhile approach when shooting to raw. Not only do you maximise signal to noise ratio, but you also maximise your data and capture the maximum tonal detail possible for your subject. It is far better to overexpose (while avoiding highlight clipping) and then reduce the brightness in post processing than it is to underexpose at the point of capture and then try to brighten everything up. A "correct" exposure is also fine, but underexposing and then correcting that underexposure is not ideal for IQ, and given what we spend in money on our cameras, our lenses, our tripods, our lighting, and time on our patience, our techniques and our effort, we should care about that.

So, back to HTP. It stands for "Highlight Tone Priority", but what that specifically means is that it tries to protect your highlights by being very cautious (1 stop cautious) about your exposure. Well that's fine and dandy but, it does this by "secretly" underexposing the (raw) capture by one stop. Bye bye ETTR for one thing. I'll now try to get off that soapbox and move on. Rather than look at when you should use HTP I'd like first to look at when you shouldn't. Here are some examples....

1. You do not need to use HTP when you shoot to raw.
Why not? Because all that HTP does is underexpose the capture at the sensor by one stop by reducing the gain (the ISO) that the camera actually uses. The camera will pretend to you that you are capturing a correct exposure and the histogram will even look like you are, but the truth is that the camera will be underexposing and then pushing the exposure for you. Regardless of what appears within the camera your raw data will be underexposed by 1 stop compared to what you thought you were getting. You could accomplish an "identical" raw capture by shooting with identical settings and making the decision for yourself to "underexpose" by one stop. But you get to choose how you effect that 1 stop safety margin. You might knock 1/3 stop off your ISO, speed up the shutter 1/3 stop and close down the aperture by 1/3 stop. The point is that you should be in control of how much safety margin you want to build in to protect the highlights and you should be control of how you accomplish that.

2. You need HTP even less when you shoot raw and do not use DPP to process.
Why? Because, as far as I know, only DPP has the magic tone curve built in to truly bring any value to the feature. If you use ACR or Lightroom (same thing really) then you will get the 1 stop underexposure at the sensor and ACR/Lightroom will invisibly double the pixel values to hide the underexposure. You gain nothing at all that you could not have accomplished by underexposing by one stop, in the manner of your choosing, in the first place.

3. You do not need HTP when there are no important highlights in the scene.
Why not. HTP is only there to protect the highlights and that protection comes at the cost of underexposing everything else in the shadows and mid tones that then needs to be boosted to restore a "correct" exposure for those parts of the image. Remembering those ETTR articles, no good will come of such things. Also, the higher the ISO you are needing to use, the more grim the effect of this needless underexposure will be. Shooting at 200 ISO (secretly = 100 ISO) there may be little enough of concern, but if you need to be shooting at 800 ISO or 1600 ISO then you should start to be concerned about noise, and posterisation, and doing everything you can to minimise them.

4. You do not need HTP when the light is constant and you can comfortably meter and set your exposure accurately (manually).
Why not. In conditions of constant, even lighting - clear sunny day with blue skies, sunny but hazy day, light overcast day or heavy overcast day, the lighting will be changing very little from one minute to the next, or even from one hour to the next. If the lighting is constant you will easily be able to set a manual exposure that will serve you for a good long while. You will be able to get to that exposure by whatever means you are comfortable with - any metering mode you like - just fire a test shot, chimp the histogram and adjust until you are within spitting distance of clipping something. In fact, if you find just a little clipping (blinking highlight warning) that may not itself be a problem, especially if it is not on your subject, or is in an area that can, and will, be cropped out. In any case, you can perform highlight recovery on small clips. You will have a perfect ETTR exposure with none of that HTP monkey business screwing around.

So, when should you use HTP? Well, having eliminated the above, that only leaves occasions when you shoot to JPEG, in conditions of variable lighting, when you have important highlight detail in the subject/scene, and you do not have the time to meter/adjust/chimp/adjust when taking a shot and are therefore relying on autoexposure to get it right for you.

Let me just leave you with one example, when not to use HTP, regardless of whether you are shooting to raw or JPEG. Picture this - It's a bright, sunny day with clear blue skies and the sun at your back. You can set a manual exposure that derives from the Sunny 16 Rule very easily. You won't even have to meter anything or check your histogram. For those unfamiliar with the rule, it states that in conditions I've just described, with an aperture of f/16 your shutter speed will be the reciprocal of your ISO. e.g. you could shoot at f/16, 1/800, 800 ISO and you would have a "perfect" exposure. This may not be an ETTR exposure, unless there was bright white in the scene, but it would be a perfectly fine capture regardless. Of course, f/16 is a bit of a weird choice so it might be better to go with something like f/8, 400 ISO, 1/1600, which would give you a nice balance between noise, DOF, lens IQ and freezing shake and subject movement. So there you go, exposure sorted and highlights will be preserved. There is absolutely no need to use HTP in order to protect your highlights in this scenario.

If you want any easy method to set a manual exposure in conditions other than "Sunny 16", very simply, hold up your palm so it is facing the same light as the light hitting your subject/scene and set a manual exposure by metering from your open palm and set an exposure at +1 1/3 stops above the middle. This is just like using a grey card except you don't have to buy it, it never gets lost and you will always have it with you. With a long lens that might be tricky, but I manage with my 100-400 at 400mm and with the lens hood in place. Just make sure the lens hood is not casting a shadow over your palm. You use your palm, rather than some other body part, since it does not tan and is thus a constant reference throughout the year. You dial in +1 1/3 stops because your palm is more reflective (brighter) than a standard grey card. Heck, if you're one of those autoexposure guys you could dial in +1 1/3 stops EC and then do a quick AE lock off your palm and you'd be set.

[Roger Clark]

Let me just leave you with one example, when not to use HTP, regardless of whether you are shooting to raw or JPEG. Picture this - It's a bright, sunny day with clear blue skies and the sun at your back.

Hi Tim,
Great writeup. I agree with most everything you say, except in my experience, there are exceptions. I looked through my images to see where I was using exposure compensation. Almost always I underexpose relative to the meter when a bird/animal has white feathers/fur. For example, cheetahs on the Serengeti in full sun: their white fur can sometimes saturate. Birds with white feathers: I usually underexpose a little, though often by only 1/3 stop. Then in tricky lighting, especially white birds on dark/changing backgrounds were you don't have time to meter and check histograms. Examples:

Egret in flight with darker background -1.5 stops:
http://www.clarkvision.com/galleries...728.b-600.html
I had determined from other exposures that day that -1.5 stops was needed. This of course
is camera dependent.

Here is one where light was changing fast and I had little time to react and get it right (-1.0 stop):
http://www.clarkvision.com/galleries...149.f-700.html

Another situation where you might use HTP is following subjects in and ut of shade with vastly changing light and backgrounds. Metering systems can fail in those situations.

So in such situations HTP might be a choice. But as you say, this only works if you are shooting jpegs or your raw converter processes the HTP info correctly.

Regarding metering off your hand: I thought the typical hand was similar to 18% gray? (I haven't tested it, but that's what I've read.) What I do is find something stable in the area that I can easily return to to check exposure, then take test exposures and adjust compensation until the exposure is correct then work in manual exposure. Example, this bear at Brooks falls:
http://www.clarkvision.com/galleries...757.b-800.html
I metered and tested exposure off the white water in front of the bear, then note the exposure and what the compensation needle said (e.g. +1 stop). Then every 10 or 20 minutes, I would return to that spot and check that the meter still read the same thing. I got several days of perfect exposures at the falls despite the bears moving in and out of the white water. I could meter off the bear, but they kept changing angles to the sun and different bears had different fur. Metering off the white water from the falls was a good standard.
So picking something in the scene to meter on works well especially with longer lenses, and it does not have to be 10% gray.

[Tim Dodd]

Ah, there are always exceptions. One thing I did not add when talking about Sunny 16 is that where your scene is a snow scene, or you are at the beach with near-white sand and highly reflective water you may need to hold your exposure back by up to 1 stop because the high reflectivity of the surroundings will create brighter ambient conditions than a more "average" scene, but I was trying to be brief, and keep things to the basics. I guess sunshine over the Serengeti is just a mite fiercer/brighter than sunshine at 51 degrees North, as I am, and if the surrounding conditions are very pale you will have that extra reflectance turning up the wick. Nonetheless, a manual exposure at, perhaps, "Sunny 16" -1/3 or -2/3 would have suited well for most of the day, other than when shooting creatures in the shade. HTP would not be the answer, just take the edge off the exposure when you need to.

I took a look at your egret shot - terrific shot :) - If I may say, you made your challenge more demanding, I suspect, by using autoexposure. It's conditions just like that where using manual makes things so much simpler. Assuming you knew you would be shooting in full sunshine (I don't know if that was full on Sunny 16 type sunshine or something a bit less) you could have had your manual exposure already set up in advance, based on the incident (sunny) light. Then it would not have mattered one jot whether the background was black shadows, sunlit leaves, bright sky, or anything else. Metering further and wondering about EC would not have entered into it.

Looking at the herons, it's much the same thing. You had the time and foresight to dial in some EC. Certainly setting a manual exposure accurately might have taken a few seconds longer, or maybe not, but once set you would be free to frame and compose as you saw fit, with varying amounts of bird vs background making not a scrap of difference. For example, let's assume you have your aperture and ISO fixed and the only variable is the shutter speed. Sure, you can dial in the -1.5 EC and let the camera take it from there, or you can twiddle the shutter speed dial until the meter says -1.5 stops. There is no real difference between the two, except, once your manual exposure is dialed in it is solidly locked. If the birds had spread their wings, taking up much more of the frame, manual would have held your exposure right where it should have been, whereas autoexposure would have reacted to the additional bright areas and further toned down the exposure. That is not what you want to happen. Why fight the EC dial when a correctly set manual exposure will keep things good until the lighting changes.

This is the way I like to think of the exposure challenge....

- If the lighting is constant but the scene/subject is moving or you are adjusting framing/composition then manual exposure will maintain your correct exposure while that light remains the same.

- If the light is changing (broken clouds) but the subject/scene are largely unchanging, and the mix of ratios of light to dark within the scene is constant, then autoexposure with some EC if the perfect solution.

- If the light is changing and the subject/scene/composition is changing then one way or another you are going to be twiddling dials. You could twiddle the shutter speed dial, or the EC dial. I really makes very little difference. It's one dial to twiddle and the meter needle will end up at the same position one way or the other.

My approach is to try more to get an exposure based on incident light, based on metering a subject of known reflectance, such as my palm, or to expose for the highlights and achieve an ETTR exposure by spot metering off the brightest subject of importance within the scene and then setting the exposure for that to +3 stops (Zone VIII). Either way I generally stick with manual exposure so I am in control and not fighting the vagueries of further reflective metering complications by guessing at additional EC adjustments.

If you want to calibrate your own palm then, on a fine sunny day (Sunny 16 day) set a manual exposure that satisfies the Sunny 16 conditions. Now, aim your palm towards the sun and spot (or partial) meter off the centre of your palm. Whatever the meter indicates at that point is your target to aim for when using your palm as a grey card substitute. When out in the field, having set an exposure from my palm, I might then meter off something more convenient within the scene I am facing - maybe a patch of grass for example. I may get a reading of -1/3 from the grass. That's fine. Now any time I want to run a quick exposure check I just aim at the grass instead and make sure I'm still showing -1/3. If not then I can easily adjust. That's potentially quicker, simpler, and less disturbing to wildlife than waving my arms around.

If I may, I'd like to quote from something I wrote on another forum recently....

At the end of the day I find manual exposure gives me the control I want on all fronts. If the lighting is constant I also find manual exposure about a million times easier to use than the auto modes. Put simply, if the lighting is constant, one you've metered and adjusted once that's the end of that chore. Shoot away happily while concentrating on framing, focusing and timing. Exposure will be one less thing to worry about.

Take today as a typical example. I was out with my camera. Conditions were bright/sunny with a little haze but no clouds. The light was barely changing at all, maybe dropping 1/3 stop every 30 minutes as the sun went down. I was walking along a dusty path, fairly pale and maybe about 1 1/3 stop above middle grey in brightness. To my left was a dark hedgerow, maybe a stop or more below middle grey. To my right was a grassy field, perhaps bang on middle grey in tone. Above me was the hazy blue sky, about 1 stop above middle grey. My camera was set with manual exposure off the palm of my hand at +1 1/3 stops. I was ready to shoot anything that appeared anywhere within a 180 degree field of view before me, both left/right and up/down. My exposure was set. Whether a crow flew by or an egret my exposure would be correct. No need to worry about the tone of my subject. No need to worry about the tone of the background, or if it was a mixture of tones. No fiddling around with EC or worrying about metering mode. Just see it, aim, focus, fire. That's why I like manual exposure.

[Jay Gould]

Gentlemen, Tim and Roger, thank you very much!!!

I have read what you have written TWICE and I will read it a few more times :D .

That is exactly what I and I am sure many other beginners to intermediate photographers need to read and then go apply to increase our own photographic abilities.

Thanks again.

[Tim Dodd]

Cheers, Jay.

At the risk of labouring this manual exposure malarky, I have uploaded an album of 90 images shot between 15:48 and 16:23 one afternoon. They are nothing to do with birds, although they are of something or other in flight. Each and every image was shot with an identical manual exposure - 200 ISO, f/8, 1/640 - and have been produced by Lightroom from the raw files with no edits at all other than to resize the images to 800x533.

http://picasaweb.google.com/EezyTige...OjLrriDkpOxqQE#

You will note that despite subjects of starkly differing tonal content and a background varying from almost 100% blue sky to 100% snow, the exposures are all absolutely spot on. I would have been absolutely wasting my time trying to shoot this lot with anything other than manual exposure. If you have the luxury of this much control over your exposures you seriously do not need HTP :).

FWIW they were shot with my 40D and 100-400 lens, nearly all at 100mm (try doing that with your 400/5.6L :) )

[Jay Gould]

Cheers, Jay.

At the risk of labouring this manual exposure malarky, I have uploaded an album of 90 images shot between 15:48 and 16:23 one afternoon. They are nothing to do with birds, although they are of something or other in flight. Each and every image was shot with an identical manual exposure - 200 ISO, f/8, 1/640 - and have been produced by Lightroom from the raw files with no edits at all other than to resize the images to 800x533.

http://picasaweb.google.com/EezyTige...OjLrriDkpOxqQE#

You will note that despite subjects of starkly differing tonal content and a background varying from almost 100% blue sky to 100% snow, the exposures are all absolutely spot on. I would have been absolutely wasting my time trying to shoot this lot with anything other than manual exposure. If you have the luxury of this much control over your exposures you seriously do not need HTP .

FWIW they were shot with my 40D and 100-400 lens, nearly all at 100mm (try doing that with your 400/5.6L :) )

Hi Tim, I do not think there is ever any risk of labouring this manual exposure malarky; not when you are trying to teach a hard head like me! :D

Every time I finally settle on the idea of selling the 100-400, first Al and now you come along and show me why I should keep my lens! :p I just put another post on the Canon 400mm f/5.6 vs. 100-400mm zoom thread about this very issue as a result of a discussing with Jim Neiger.

Regarding manual exposure, Roger described how he metered for the bears at Brooks Falls; Tim, please described how you metered in the snow. I am going to be in the snow in Antarctica for several weeks.

Cheers,

[Alfred Forns]

Jay You can't compare the two lenses ... totally different. btw Jim Neiger was making sharp images with a 10D when most of us were struggling ..... adjusted using a different technique and worked.

...btw for snow just meter on the snow and open one and one half stops

[Jay Gould]

Jay You can't compare the two lenses ... totally different. btw Jim Neiger was making sharp images with a 10D when most of us were struggling ..... adjusted using a different technique and worked.

...btw for snow just meter on the snow and open one and one half stops

Al, I know the lenses are totally different; however, at the end of the day I can only carry one! :)

I have to make a choice; simple as that. I also know that at the end of the day I - I - have to make the choice with all of the valuable assistance I am receiving since joining BPN. Thanks everybody.

I am really looking forward to spend three days alone with Jim.

[Alfred Forns]

The zoom is more versatile but imagine it will depend on the other lenses you have.

Will be fun with Jim Will open your eyes to flight photography !!!

[Roger Clark]

Al, I know the lenses are totally different; however, at the end of the day I can only carry one! :)

I have the 100-400, and mine simply isn't sharp. If you have a sharp one, keep it!
Note also the push pull zoom pumps air into the lens and thus could pump dust into the camera body.

But having said that, and you say you can only carry one, for the amount one spends to go to Antarctica, I would take my 500. But as you say, if it is too heavy and you need a lighter lens, I would take a 300 f/2.8. The 300 f/2.8 is an amazingly sharp lens, much sharper than the 100-400. Wide open you have impressively narrow depth of field for isolating subjects, and you can still do very well with 1.4 and 2x TCs and still have good autofocus. So you get 600 mm f/5.6 That's a great range for not a lot of weight an bulk. It's the lens I would take on such a trip if I couldn't take the 500.

[Jay Gould]

I have the 100-400, and mine simply isn't sharp. If you have a sharp one, keep it!
Note also the push pull zoom pumps air into the lens and thus could pump dust into the camera body.

But having said that, and you say you can only carry one, for the amount one spends to go to Antarctica, I would take my 500. But as you say, if it is too heavy and you need a lighter lens, I would take a 300 f/2.8. The 300 f/2.8 is an amazingly sharp lens, much sharper than the 100-400. Wide open you have impressively narrow depth of field for isolating subjects, and you can still do very well with 1.4 and 2x TCs and still have good autofocus. So you get 600 mm f/5.6 That's a great range for not a lot of weight an bulk. It's the lens I would take on such a trip if I couldn't take the 500.

Hi Mate, that is an interesting twist on the subject! :)

I do have the 300 on my "under consideration" list; it was the f/4 @ 2.6lb/8.7". Aside from a bit :eek: of a price bump ($1,200 to $4,100) we also bump from 2.6lb/8.7" to 5.6lb/9.9".

You have indicated earlier that HH the 300 with your camera bodies isn't an issue.

You lens testing chart/results are fascinating - you are amazing!! The scientific levels/presentations are beyond this simple lawyer's abilities; thanks for drawing the conclusions!

We know what happens when one "assumes" so I will not assume!

It appears that among the results of your tests is the elimination of the notion that the 2x teleconverter should be shunned and only the 1.4 considered. No assumptions; correct?

In your 500mm tests you used the Kenko and not the Canon teleconverters also dispelling the notion that one must use the Canon equipment.

Turning to the 300mm, is it a reasonable interpretation of the data that you have demonstrated with the 300 f/4 that it is sharper basically through the entire 100 - 400 range, both alone and with the 1.4 and 2x converters?

It isn't in your test results so now we go to your vast experience.

At f/4 and above is the 300 f/4 as sharp as the 300 f/2.8 recognizing that f/4 is a 1-stop slower lens?

Same question using the 300 f/4 with either the 1.4 or the 2x teleconverter.

I cannot ask you to add the 400 f/5.6 into the mix because you do not have that lens, if I recall correctly. Can anyone else who has used the various lenses under discussion add to this process?

Is the 400 f/5.6 as sharp as the 300 f/4?

At the extreme, using the 300 f/4 on the 50D with a 1.4 teleconverter will gives you - gosh just like a test at school - f/5.6 at at 480mm (1.6 cropped sensor) bumped 1.4 for the teleconverter makes it a 672mm and with the 2x it becomes a 960mm. :confused: Did I get that right?

Realistically, does an avid amateur like myself need more than that?

At the end of the day, isn't the 300 f/4 a better compromise if I sold the 100-400 than the 400 f/5.6, and also bought the 2x converter?

And, finally, in a given situation, would you rule out stacking the 1.4 and the 2x and resulting in too much loss of IQ?

Roger, you are challenging me to work through all of this; thanks!

[Tim Dodd]

Regarding manual exposure, Roger described how he metered for the bears at Brooks Falls; Tim, please described how you metered in the snow. I am going to be in the snow in Antarctica for several weeks.

Cheers,

For these shots, without metering anything, I started out with a manual "Sunny 16" exposure setting that gave me a nice balance between DOF and lens IQ (f/8), a reasonable shutter speed to freeze action (1/800) and an ISO setting that allowed those two to work together (200 ISO).

I fired a test shot, checked the histogram very carefully to see what was happening at the right hand edge, and also checked the preview image for blinking warnings of highlight clipping. I had a little rooom at the right hand edge and nothing was blinking. I opened up 1/3 stop by adjusting shutter speed to 1/640 and fired another test shot. Bingo! Just the merest hint of a few blown pixels - nothing that would spoil the image, and if I was bothered then highlight recovery would save them. That was me done. Now to shoot some pictures :).

You may wonder how I ended up at 1/3 stop brighter than "Sunny 16", given the snowy conditions and dazzling clear sky. Well, remember this was winter sun - shot in January in the northern hemisphere - and it was around 16:00 so the sun was not that high in the sky any more. Looking back at the histograms I do note that, while I had a little clipping at the start of the series, all signs of clipping had vanished by the end, 30 minutes later. However, the difference was no more than 1/3 stop, certainly not enough to warrant remetering or adjusting the exposure.

If I wanted to deliberately meter the snow, rather than use the suck it and see estimation I used above, I would spot meter the brightest part of the sunlit snow and set an exposure of +3 stops for the snow. +3 stops is just before the onset of clipping, so, if I place the brightest thing of importance within the scene just within the clipping point then I should have a very nice (ETTR) exposure. I think the advice given earlier by Alfred to dial in only +1.5 stops is really very conservative. If the snow is at +1.5 stops then what would you have occupying the additional 1.5 stops of headroom above that, I wonder? To me, that is wasted dynamic range and would needlessly push the shadows and blacks further into the abyss, where detail is lost. Remember, a palm is at around +1 1/3 stops. Surely snow is brighter than a palm by more than 1/6 of a stop. If you recall that BIF photo I posted in post #43, that was exposed by metering the brightest part of the sky at +3 stops. Look at the histogram that resulted. Can you get a better histogram than that? Whatever your subject, snow, sky, paintwork, water, feathers etc. etc., place the very brightest thing for which you need to retain detail/texture at +3 stops and everything else will fall into place below that. If you do want to be cautious then try + 2 2/3 or +2 1/3 instead, but no less.

Of course, because I had the sun behind me, I could equally as well have used my palm and metered that at +1 1/3 stops for a similar result. Whatever metering approach you use, there is never any harm in double checking your histogram and searching for blinkies. It is also worth remembering that not all blinkies are bad; you need to determine what part of the scene they represent. For example, specular highlights shining off chrome, steel, glass, water, even white (or any colour) gloss paintwork etc. are simply going to be crazy bright. Ditto any light sources within the composition. It's not like there will be any detail in there that you simply have to retain. Is it going to damage the picture if a light bulb or a small direct reflection of the sun shows as 255, 255, 255? I think not. Even if a little of the snow is blown - say 1% or 2%, will that destroy the image? Can you pull it back, assuming you shoot raw?

If you want to put this +3 stops thing to the test for your own assurance, and to confirm that it applies to your own gear, try this test. Grab yourself a plain white towel, cloth, jersey - anything that is a single tone and has texture. Actually, even the living room carpet should do the trick, if it is plain and not patterned. Lay it somewhere flat, in even and steady lighting. Using manual exposure, spot meter off the centre of the target and set an exposure of 0 on the meter. Focus and fire a shot. Now, by reducing the shutter speed, increase the exposure by 1 stop and fire off another shot. Do the same at +2 stops. Repeat again for +2 1/3, +2 2/3, +3, +3 1/3, +3 2/3, +4. You may need to use a tripod, depending on shutter speeds, because you want to retain sharpness/clarity of the texture. If you like, you could shoot in raw+JPEG, just to compare the results from each.

Now load up the image files into your favourite raw processor and take a look at the images themselves, the histograms and the highlight clipping warnings. My personal favourite is Lightroom (or ACR). Compare the images and histograms etc. and look for the first indications of highlight clipping. My guess is that the +3 stop exposure will be clean, at least in the raw file. I'm not sure about the JPEG and, personally, I really don't care, but it might matter to you. How does +3 1/3 look? Maybe there will be some signs of clipping but I expect texture will still be visible. How easily can you make the clipping warnings vanish by use of the highlight recovery tool? I bet it won't take much. Now repeat the checks for the +3 2/3 and +4 image files. I don't know what you'll find but it wouldn't surprise me if you can get something worthwhile from at least the +3 2/3 stop images. +4 will probably be taking things just a bit too far. Anyway, whatever you come up with in your results, you will know how much headroom you have above a metered "0" exposure while (a) fully retaining all detail; (b) being able to recover detail that was clipped.

[Roger Clark]

It appears that among the results of your tests is the elimination of the notion that the 2x teleconverter should be shunned and only the 1.4 considered. No assumptions; correct?

I find the Kenko pros TCs to be quite good. But in the last couple of years I have moved to the canon TCs wich I think are a tad sharper.

In your 500mm tests you used the Kenko and not the Canon teleconverters also dispelling the notion that one must use the Canon equipment.

Yes. I've used the kenko pro 300s on 70-200 f/4 L, 300 f/4 L and 500 f/4 L.

Turning to the 300mm, is it a reasonable interpretation of the data that you have demonstrated with the 300 f/4 that it is sharper basically through the entire 100 - 400 range, both alone and with the 1.4 and 2x converters?

I'm not sure with you mean here. the 300 f/4 is fixed. If you mean do I see the 300 f/4 sharper than the 100-400 zoom lens, then yes, at least for my 100-400.

It isn't in your test results so now we go to your vast experience.

At f/4 and above is the 300 f/4 as sharp as the 300 f/2.8 recognizing that f/4 is a 1-stop slower lens?

Same question using the 300 f/4 with either the 1.4 or the 2x teleconverter.

The 300 f/2.8 is much sharper than the 300 f/4 in my experience. I've had the 300 f/2.8 less than a year. but boy is it impressive. In the Canon lens MTF charts, it is the top performing lens in the entire line. The 300 f/2.8 is sharper at f/2.8 than the 300 f/4 at f/4. Adding TCs and the f/2.8 lens is always sharper than the f/4 lens in my experience.

I cannot ask you to add the 400 f/5.6 into the mix because you do not have that lens, if I recall correctly. Can anyone else who has used the various lenses under discussion add to this process?

Is the 400 f/5.6 as sharp as the 300 f/4?

While I have not used the 400 f/5.6, I have friends who have compared it to the 300 f/4 and their images indicate the 400 f/5.6 is sharper.

At the extreme, using the 300 f/4 on the 50D with a 1.4 teleconverter will gives you - gosh just like a test at school - f/5.6 at at 480mm (1.6 cropped sensor) bumped 1.4 for the teleconverter makes it a 672mm and with the 2x it becomes a 960mm. :confused: Did I get that right?

I disagree with the crop factors. It is a field of view crop, not an actual magnification. Crop factor does not get you more pixels on the bird, for example. The 300 f/4 plus 1.4x TC gets you to 420 mm f/5.6. That's pretty nice, bur for birds you always need more. The 300 f/2.8 + 2x TC gets you 600 mm at f/5.6 and that is a lot closer. You can also stack TCs and get even closer, and still have some autofocus as only one TC gets reported to the camera. So you could have 2 2x TCs and get 1200 mm f/11 with the 300 f/2.8. I have many images with stacked 1.4 and 2x TC on my 500 mm. It gets tough to hold the system steady, but I have made beautiful 16 x 20 inch prints that are hanging on people's walls using stacked TCs.

Realistically, does an avid amateur like myself need more than that?

Depends on how avid you are. The 500 mm was a "life changing" lens for me. I bought it for astrophotography. then realized how good it is for wildlife and how much more fund wildlife photography is. Also gets me more exercise. ;-)

At the end of the day, isn't the 300 f/4 a better compromise if I sold the 100-400 than the 400 f/5.6, and also bought the 2x converter?

That is the route I went. I didn't sell the 100-400 (still have it-it gets used very little). I wanted IS, so for me the 300 f/4 was better than the 400 f/5.6 with no IS. But I often find the 300 f/4 is not enough. So for those times I travel and can't take the 500, the 300 f/2.8 is a better lens for me. I only go to the 300 f/4 if I'm not expecting to do much wildlife or weight is too much of a consideration. For example, on some business trips, I walk into the meeting with a big lowepro backpack with tripod on it, and get a lot of funny looks. But people are getting used to me with that.

And, finally, in a given situation, would you rule out stacking the 1.4 and the 2x and resulting in too much loss of IQ?

Like I said above, I stack TCs when needed. You just need to be very steady.

Roger, you are challenging me to work through all of this; thanks!

For a trip to Antarctica: I would take at least a 300 f/2.8. It could be a life changing lens for you too. Not only with photos, think of the extra exercise! That's good both ways. I constantly add more to my pack to carry more weight. One goal is to still be hiking in the mountains at 12,000 feet with a 40 pound pack when I'm 72. How about 30 pounds at 80? I think it's realistic, and I'll try and beat that.

Good luck!

[Arthur Morris]

If I may, I'd like to quote from something I wrote on another forum recently....

If I may, I'd like to quote from something I wrote on another forum recently....


Quote:

At the end of the day I find manual exposure gives me the control I want on all fronts. If the lighting is constant I also find manual exposure about a million times easier to use than the auto modes. Put simply, if the lighting is constant, one you've metered and adjusted once that's the end of that chore. Shoot away happily while concentrating on framing, focusing and timing. Exposure will be one less thing to worry about.

Take today as a typical example. I was out with my camera. Conditions were bright/sunny with a little haze but no clouds. The light was barely changing at all, maybe dropping 1/3 stop every 30 minutes as the sun went down. I was walking along a dusty path, fairly pale and maybe about 1 1/3 stop above middle grey in brightness. To my left was a dark hedgerow, maybe a stop or more below middle grey. To my right was a grassy field, perhaps bang on middle grey in tone. Above me was the hazy blue sky, about 1 stop above middle grey. My camera was set with manual exposure off the palm of my hand at +1 1/3 stops. I was ready to shoot anything that appeared anywhere within a 180 degree field of view before me, both left/right and up/down. My exposure was set. Whether a crow flew by or an egret my exposure would be correct. No need to worry about the tone of my subject. No need to worry about the tone of the background, or if it was a mixture of tones. No fiddling around with EC or worrying about metering mode. Just see it, aim, focus, fire. That's why I like manual exposure.

There is much misinformation and over-analysis in the posts above. I wish that I had time to respond and comment on all of it but I do not. I could not however, let the information above stand as it is so wrong. (Tim, please do not take it personally.) Jeez, I just read the whole thing more carefully and it is much worse than I thought.
First off, the amount of lightchanges by several stops as you work more and more off sun angle.

Second, the statement that a crow needs the same amount of light to be properly exposed as a (sic: white) egret is incorrect. Period. By miles.

I refer all who wish to learn exposure theory to the reprinted "The Art of Bird Photography." Simply put, and this is universally accepted knowledge: in the same light, bright white birds need one stop less light to be properly exposed than a middle tone (don't believe me: see John Shaw's "Sunny f/22" in his first book. And black birds need 2/3 to one stop more light than a middle tone.

[Jay Gould]

Artie, without even touching on the content of what you have said, I am so glad you referred to John Shaw. I am participating in a 3-day workshop taught by him in October in Bishop, California: Eastern Sierra Fall Colors. http://www.mountainlight.com/workshops/091001-1008.html

I am quite excited about the experience.

[Jim Neiger]

If I may, I'd like to quote from something I wrote on another forum recently....


Quote:

At the end of the day I find manual exposure gives me the control I want on all fronts. If the lighting is constant I also find manual exposure about a million times easier to use than the auto modes. Put simply, if the lighting is constant, one you've metered and adjusted once that's the end of that chore. Shoot away happily while concentrating on framing, focusing and timing. Exposure will be one less thing to worry about.

Take today as a typical example. I was out with my camera. Conditions were bright/sunny with a little haze but no clouds. The light was barely changing at all, maybe dropping 1/3 stop every 30 minutes as the sun went down. I was walking along a dusty path, fairly pale and maybe about 1 1/3 stop above middle grey in brightness. To my left was a dark hedgerow, maybe a stop or more below middle grey. To my right was a grassy field, perhaps bang on middle grey in tone. Above me was the hazy blue sky, about 1 stop above middle grey. My camera was set with manual exposure off the palm of my hand at +1 1/3 stops. I was ready to shoot anything that appeared anywhere within a 180 degree field of view before me, both left/right and up/down. My exposure was set. Whether a crow flew by or an egret my exposure would be correct. No need to worry about the tone of my subject. No need to worry about the tone of the background, or if it was a mixture of tones. No fiddling around with EC or worrying about metering mode. Just see it, aim, focus, fire. That's why I like manual exposure.

There is much misinformation and over-analysis in the posts above. I wish that I had time to respond and comment on all of it but I do not. I could not however, let the information above stand as it is so wrong. (Tim, please do not take it personally.) Jeez, I just read the whole thing more carefully and it is much worse than I thought.

First off, the amount of light changes by several stops as you work more and more off sun angle.

Second, the statement that a crow needs the same amount of light to be properly exposed as a (sic: white) egret is incorrect. Period. By miles.

I refer all who wish to learn exposure theory to the reprinted "The Art of Bird Photography." Simply put, and this is universally accepted knowledge: in the same light, bright white birds need one stop less light to be properly exposed than a middle tone (don't believe me: see John Shaw's "Sunny f/22" in his first book. And black birds need 2/3 to one stop more light than a middle tone.

To add to what Artie says, the amount of compensation one needs varies with the intensity of light. I think most photogs don't really understand this. Manual exposure mode does put you in control and allows you to make very consistant spot on exposures. Manual is a must for bif with changing bgs.

As far as lenses go, I'm surprised the 400mmDO hasn't been mentioned. I would take that lens over the 100-400mm and the 400mm F5.6 lens anyday. The 300mm F4 simply isn't a top lens for birds. The 300mm F2.8 is a great lens, but I would take the 500mm hands down over all. I have owned all of these lenses except the DO and the 300mm F4. I still own and use the 500mm, 300mm F2.8, and the 100mm-400mm. I spent 8 weeks in Australia phoptographing birds and I used the 500mm about 95% of the time. I could have left the others at home. I fit all 3 of these lense along with two wide angles and a ton of accessories in my Think Tank Airport security rolling bag. Travel was a breeze. In the field when hiking I would ususally just carry the 500mm with tcs and flash cards in my pockets.

Jay if I were you I would get the 1D3, 500mm, and both canon TCs.

[Arthur Morris]

Artie, without even touching on the content of what you have said, I am so glad you referred to John Shaw. I am participating in a 3-day workshop taught by him in October in Bishop, California: Eastern Sierra Fall Colors. http://www.mountainlight.com/workshops/091001-1008.html

I am quite excited about the experience.

John was a guest co-leader with me about two years ago on my San Diego and Fort DeSoto IPTs. Be sure to give him a hug for me. John is a lot quieter and far more modest than me. Be sure to let us know of your experience. And be sure to give him a hug for me.

[Jay Gould]

Artie, I hope to meet you in October before I meet John. I will be doing a 3-day workshop with Jim 30 Sept, 1 & 2 October. :-)

[Jay Gould]

Jay if I were you I would get the 1D3, 500mm, and both canon TCs.

:D

Amazing, sometimes I attempt to post a message and in the preview it adds lots of icons and I have to delete them; now I get an error message that this message - before I typed this sentence is "too short. Please lengthen your message to at least 10 characters." :D:D

[Arthur Morris]

Artie, I hope to meet you in October before I meet John. I will be doing a 3-day workshop with Jim 30 Sept, 1 & 2 October. :-)

Which Jim and what workshop????

[Tim Dodd]

If I may, I'd like to quote from something I wrote on another forum recently....

Artie, if a black bird requires an exposure that differs from that for a white bird, how would you go about establishing an exposure for a very black and very white bird such as a magpie? If you had a mixed flock of black birds and white birds how would you set your exposure?

I quite agree that in an ideal world you might wish to finesse your exposure to pull out more detail from one extreme or the other of the tonal scale - I normally add about 1 stop to the nominal exposure value for the ambient light when photographing my black dog, when there is nothing in the background that would spoil - but what if you have both extremes in one subject? What if there is something else of importance in the scene that cannot accommodate a 1 stop "overexposure" just to suit the crow?

As for sun angle, I haven't conducted any empirical tests, but in the example I described earlier I had the sun at my back so the sun angle at most would have only changed between +/- 90 degrees. It isn't as though the sun would ever have been on the "wrong" side of my subject. Furthermore, when you get a subject that is broadly spherical in shape, such as a bird's body, you are going to get hotspots and cooler areas somewhere on the bird, wherever you are in relation to the light source, assuming the sun is on your side of the subject. I can tell you from my experience of shooting swans that highlight clipping point is pretty much the same whether the sun is directly behind me or significantly off to one side. If your experience is different then I am perplexed.

Imagine a cue ball for a game of pool, and a single light source behind you. You can swing that ball through a pretty broad field in front of you and somewhere in the surface of that ball you will see that light source reflected. In other words there is some angle of the surface of that ball that directly reflects the light straight to you. I don't see the curved breast of a bird, or its head or back being any different. Somewhere you will see that hotspot, even if it is not as specular as the glossy ball.

Update : I've just popped out to fire off some test shots using a substitute for a white bird. Sure enough, so long as the sun is on my side of the subject whether the subject is dead ahead or considerably off to one side does not change the exposure requirements at all. In all cases the peak of the histogram is at pretty much the same place. The height might alter from shot to shot but the clipping point is still the same regardless of angle. Here are the results, all using a single manual exposure value metered at +3 off the brightest area of the towel.....

http://picasaweb.google.com/EezyTige...CIyiiY628Pz4Jg#

As you will see, far from being a difference of several stops due to sun angle, the difference is not even 1/3 stop. Yes, there are more pixels that are brighter with the subject directly ahead, but even off to either side there are more than enough bright pixels of importance to require exactly the same exposure, no more, no less. As you may note, I have enabled the highlight clipping indicators and you will see just a small handful of pixels clipped at the +3 stops setting. That is comfortably within the realm of highlight recovery or even a simple creative reduction in the whole exposure. In short, no critical data is lost from these captures. +3 on the meter got my my ETTR exposure from all angles within that 180 degree arc.

EDIT : I've updated the online album with the same 7 images once more, this time with the exposure reduced by 1 stop on each image. Note how all the texture/detail is retained, even though it might not have been easy to see with the original exposure. I've also uploaded one more view, making it easier to compare most of the histograms at once. All of these exposures were correct, and all of them were identical. I don't know what else to say.

[Jim Neiger]

Artie, if a black bird requires an exposure that differs from that for a white bird, how would you go about establishing an exposure for a very black and very white bird such as a magpie? If you had a mixed flock of black birds and white birds how would you set your exposure?

I quite agree that in an ideal world you might wish to finesse your exposure to pull out more detail from one extreme or the other of the tonal scale - I normally add about 1 stop to the nominal exposure value for the ambient light when photographing my black dog - but what if you have both extremes in one subject? What if there is something else of importance in the scene that cannot accommodate a 1 stop "overexposure" just to suit the crow?

As for sun angle, I haven't conducted any empirical tests, but in the example I described earlier I had the sun at my back so the sun angle at most would have only changed between +/- 90 degrees. It isn't as though the sun would ever have been on the "wrong" side of my subject. Furthermore, when you get a subject that is broadly spherical in shape, such as a bird's body, you are going to get hotspots and cooler areas somewhere on the bird, wherever you are in relation to the light source, assuming the sun is on your side of the subject. I can tell you from my experience of shooting swans that highlight clipping point is pretty much the same whether the sun is directly behind me or significantly off to one side. If your experience is different then I am perplexed.

Imagine a cue ball for a game of pool, and a single light source behind you. You can swing that ball through a pretty broad field in front of you and somewhere in the surface of that ball you will see that light source reflected. In other words there is some angle of the surface of that ball that directly reflects the light straight to you. I don't see the curved breast of a bird, or its head or back being any different. Somewhere you will see that hotspot, even if it is not as specular as the glossy ball.

Update : I've just popped out to fire off some test shots using a substitute for a white bird. Sure enough, so long as the sun is on my side of the subject whether the subject is dead ahead or considerably off to one side does not change the exposure requirements at all. In all cases the peak of the histogram is at pretty much the same place. The height might alter from shot to shot but the clipping point is still the same regardless of angle. Here are the results, all using a single manual exposure value metered at +3 off the brightest area of the towel.....

http://picasaweb.google.com/EezyTige...CIyiiY628Pz4Jg#

As you will see, far from being a difference of several stops due to sun angle, the difference is not even 1/3 stop. Yes, there are more pixels that are brighter with the subject directly ahead, but even off to either side there are more than enough bright pixels of importance to require exactly the same exposure, no more, no less. As you may note, I have enabled the highlight clipping indicators and you will see just a small handful of pixels clipped at the +3 stops setting. That is comfortably within the realm of highlight recovery or even a simple creative reduction in the whole exposure. In short, no critical data is lost from these captures. +3 on the meter got my my ETTR exposure from all angles within that 180 degree arc.

Tim,

I think your test is somewhat flawed. The angle of incidence equals the angle of reflection, so the angle of the sun relative to the subject and yourself as well as the position of the subject impacts the light collected by the camera. I often wait for birds to be at the right angle to catch the light. I also often increase exposure when they aren't catching the light.

As I said earlier in this thread, the intensity of the light greatly effects the compensation needed. More intense light produces more contrast and dynamic range in the scene. This means that the difference in exposure between a black bird and a white bird will be much less in low light than in very bright light. When the dynamic range of the light reflected from a black and white bird exceeds the dynamic range of the camera, the photographer must decide if they wish to blow the whites and preserve detail in the blacks or lose detail in the blacks in order to preserve detail in the whites. In soft low light it is possible to get detail in both whites and blacks, but when the light gets brighter, the camera's dynamic range falls short.

[Jim Neiger]

Which Jim and what workshop????

He is talking about me and a custom private workshop. The educational subject matter and species pursued will be specified by Jay based on suggestions I make.

[Pete Woods]

Wow, what a read........ I know have a headache.... thanks all ;)

[Arthur Morris]

Tim,

re:

Artie, if a black bird requires an exposure that differs from that for a white bird, how would you go about establishing an exposure for a very black and very white bird such as a magpie? If you had a mixed flock of black birds and white birds how would you set your exposure?

As with film, we always need to expose for the highlights.

I quite agree that in an ideal world you might wish to finesse your exposure to pull out more detail from one extreme or the other of the tonal scale - I normally add about 1 stop to the nominal exposure value for the ambient light when photographing my black dog, when there is nothing in the background that would spoil - but what if you have both extremes in one subject?

As above.

What if there is something else of importance in the scene that cannot accommodate a 1 stop "overexposure" just to suit the crow?

As above, except if you wish to burn a white sky when exposing correctly for a black bird.

As for sun angle, I haven't conducted any empirical tests, but in the example I described earlier I had the sun at my back so the sun angle at most would have only changed between +/- 90 degrees. It isn't as though the sun would ever have been on the "wrong" side of my subject. Furthermore, when you get a subject that is broadly spherical in shape, such as a bird's body, you are going to get hotspots and cooler areas somewhere on the bird, wherever you are in relation to the light source, assuming the sun is on your side of the subject. I can tell you from my experience of shooting swans that highlight clipping point is pretty much the same whether the sun is directly behind me or significantly off to one side. If your experience is different then I am perplexed.

All that you need to do is put three big cards out and propped up at the same angle. One in front of you down the sun angle, one 90 degrees to your left and facing you, and one 90 degrees to your right and facing you. Then you can tell me how wrong you were.

Imagine a cue ball for a game of pool, and a single light source behind you. You can swing that ball through a pretty broad field in front of you and somewhere in the surface of that ball you will see that light source reflected. In other words there is some angle of the surface of that ball that directly reflects the light straight to you. I don't see the curved breast of a bird, or its head or back being any different. Somewhere you will see that hotspot, even if it is not as specular as the glossy ball.

I amm not very good at imagining. I am however very good at getting the right exposure and at teaching others to do the same thing. Again, you are way over-complicating matters.

Update : I've just popped out to fire off some test shots using a substitute for a white bird. Sure enough, so long as the sun is on my side of the subject whether the subject is dead ahead or considerably off to one side does not change the exposure requirements at all. In all cases the peak of the histogram is at pretty much the same place. The height might alter from shot to shot but the clipping point is still the same regardless of angle. Here are the results, all using a single manual exposure value metered at +3 off the brightest area of the towel.....

There are so many errors in the above paragraph that I simply do not have time to mention them.

http://picasaweb.google.com/EezyTige...CIyiiY628Pz4Jg#

As you will see, far from being a difference of several stops due to sun angle, the difference is not even 1/3 stop. Yes, there are more pixels that are brighter with the subject directly ahead, but even off to either side there are more than enough bright pixels of importance to require exactly the same exposure, no more, no less. As you may note, I have enabled the highlight clipping indicators and you will see just a small handful of pixels clipped at the +3 stops setting. That is comfortably within the realm of highlight recovery or even a simple creative reduction in the whole exposure. In short, no critical data is lost from these captures. +3 on the meter got my my ETTR exposure from all angles within that 180 degree arc.

I understand that with bright highlights the correct off-angle EXP may be the same (to preserve the highlights) well off of sun angle, but do understand that the middle and dark tones will be that much more underexposed. And most improtantly, mmy original statement did not mention the word white: First off, the amount of light changes by several stops as you work more and more off sun angle.

I regret that I do not have the time or the inclination to follow your link.

EDIT : I've updated the online album with the same 7 images once more, this time with the exposure reduced by 1 stop on each image. Note how all the texture/detail is retained, even though it might not have been easy to see with the original exposure. I've also uploaded one more view, making it easier to compare most of the histograms at once. All of these exposures were correct, and all of them were identical. I don't know what else to say.

Tim with all due respect, I just checked in hopes of seeing some of your images. To date, you have posted zero images. As you profess to know so much and have so much experience, we would all love to see some of your images.

[Tim Dodd]

Jim, you are quite correct when you say that in strong, harsh light the camera's dynamic range might be exceeded and yes, you do have to choose which end of the tonal scale to sacrifice. Since my speciality, if I even have one, is not birds, but weddings, I have to deal with those tonal extremes often. For me, the bottom line is to protect the details in the wedding dress. Highlight tones always take priority for me. Everything else just has to end up where it may, including the groom's suit.

The thing is, when shooing a wedding, and assuming I have the luxury of constant light, I can set a manual exposure that will hold the details in the bride's dress from most shooting angles. She has curves; the dress has curves; somewhere on that dress there will be bright areas that need to hold detail (unless the sun is behind her) and that's what I use to confirm my exposure. Every time she appears in a photo under the same lighting, even if many minutes apart, she will have the same exposure, the same skin tones etc.. If her husband joins her then the exposure will not be thrown off in any way. It doesn't matter if I'm shooting the bride on her own, the groom on his own, or 100 guests dressed in every variety of colour and tone imaginable. If the light is the same they will all get the same exposure, the highlights won't get blown and their skin tones will all look good. I will be ready to capture the scene well, over and over again. On a bright, sunny day, I know that "Sunny 16" will get me what I need, every time, perhaps with those small adjustments for snow or white sand, but other than that I'm set. Regardless of how much light the groom's suit sucks up, he will still want an exposure that is correct for his face, and that will be an exposure based very closely on whatever reading I get from my own palm. I do not want to overexpose his face by a stop just so we can see unimportant details in his black suit.

If I shoot motorsport, all the same arguments apply - for any given ambient light conditions there will be a "correct" exposure that will allow me to capture a whole scene, including grass, track, white cars, black cars, silver cars, people and everything else as perfectly as possible. That is the exposure I seek. That is the exposure I get by metering from my palm at +1.3 stops or the brightest thing of importance in the scene at +3 stops. If, God forbid, my palm meter fails me then a quick check of the histogram and a search for blinkies on a white car will put me on the right track. Certainly, my exposures for those ski shots were faultless, IMHO, even in harsh contrasty light. Did it matter to my exposure success whether the shots were taken with the sun over my left shoulder or my right? No. Would it have mattered if I'd taken shots with the sun directly behind me? No. Did it matter when the angles of the sunlight opened up wider? No.

Here's a shot taken on a clear sunny day using a Sunny 16 exposure of 100 ISO, f/10, 1/250. According to the histogram and the clipping indicators I think I got this pretty much bang on. I just hope the image shows this time.....



In this shot, with the sun at pretty much 9 degrees, relative to my subject, and relative to the previous photo, I once again have a Sunny 16 exposure. The aperture and shutter speed have altered, this time to f/8 and 1/400 at 100 ISO, but the adjustments balance each other out to retain a Sunny 16 exposure....



Where is the need for an exposure adjustment of potentially "several stops" due to changing angle of the sun?


Clearly bird photography has different rules and requirements. Maybe one day I'll understand why.

I'm really sorry about any time I've wasted and any offense I've caused by allegedly spouting a load of gibberish. I guess we all have our own ideas about what works for us. I've shared what works for me. If my approach doesn't suit others here then fair enough. I think I've contributed all that I can to this thread, so I shall retire from it now.

Good luck to everyone. Bye.

[Jay Gould]

He is talking about me and a custom private workshop. The educational subject matter and species pursued will be specified by Jay based on suggestions I make.

I am very excited about spending three days in a custom private workshop with Jim. I feel like I am back in school again. During the next six months I will be immersed in lots of writings, Artie - I have ordered and I am waiting to receive BAA 1 & 2 (in the meantime I am reading the back archives while rehabilitating my knee), I have a bunch of books including John Shaw's Landscape book and several pertaining to Photoshop that I am going to get through.

I am planning to have at least graduated from a beginner to a beginning intermediate :) photographer by the time I am with Jim and John; I am also going to spend a day with Robert O'Toole in California after my workshop with John.

Cheers, Jay

Finding BPN has expanded my horizons greatly and if some of the experts on BPN have their way with me pertaining to camera gear, it is going to lighten my wallet too. :D

Oh well, I am a strong supporter of the SKI club.

[Leonard Malkin]

I post twice to Art Morris, asking whether a gimbal or ball head would help me track BIF (no answer) and then in response to his "wrong wrong wrong" response re using all 9 focus points on the 40D, I quote him directly that older folks like us need to use all because tracking with the center point is too difficult (no response). Are my posts getting lost somewhere?

[Jim Neiger]

I post twice to Art Morris, asking whether a gimbal or ball head would help me track BIF (no answer) and then in response to his "wrong wrong wrong" response re using all 9 focus points on the 40D, I quote him directly that older folks like us need to use all because tracking with the center point is too difficult (no response). Are my posts getting lost somewhere?

Leonard,

I would suggest shooting the 40D and 100-400mm handheld instead of with either type of head on a tripod. If you use the tripod, the gimbal head is better. I also suggest using only the center AF point, not multiple points or with AF expansion. Center point only will give you much better control exactly where you focus. This will help you maintain focus on the bird when the bgs are varied and also where on the bird you focus. Using multiple points usualy results in loss of control. The camera is more likely to focus on the bg or on the near wing of the bird when multiple points or expansion are used. This may still happen with center point only, but then it will be because you missed, not because the camera focused in the wrong place.

[Arthur Morris]

I post twice to Art Morris, asking whether a gimbal or ball head would help me track BIF (no answer) and then in response to his "wrong wrong wrong" response re using all 9 focus points on the 40D, I quote him directly that older folks like us need to use all because tracking with the center point is too difficult (no response). Are my posts getting lost somewhere?

Hi Leonard, I am sorry that I missed your questions. I have been swamped and am getting ready for a six week SUV trip. In most situations, if you are using a 100-400 it is usually best to handhold. As for using all points because of old age, I wrote what you quoted me on several years ago when I was using the MII bodies. I am fine with folks using the 45- or 9-point AF if they are having trouble hodling focus as long as they are not using MIII bodies where 45-point for flight is close to worthless.

You ask if your posts are getting lost somehwher. Do you see them above? Do note that this is my 6762nd post here on BPN so I have been managing to help a few folks out.

[Leonard Malkin]

Hi Leonard, I am sorry that I missed your questions. I have been swamped and am getting ready for a six week SUV trip. In most situations, if you are using a 100-400 it is usually best to handhold. As for using all points because of old age, I wrote what you quoted me on several years ago when I was using the MII bodies. I am fine with folks using the 45- or 9-point AF if they are having trouble hodling focus as long as they are not using MIII bodies where 45-point for flight is close to worthless.

You ask if your posts are getting lost somehwher. Do you see them above? Do note that this is my 6762nd post here on BPN so I have been managing to help a few folks out.

Thanks for answering. I didn't realize you're so busy.

The one point that jumps out is your statement that the 45-point for BIF with MIII bodies is worthless. Have I missed something in the forum or your books (both of which I have)?

[Arthur Morris]

I did not say that 45-point with the MIII was worhtless, I said that it was worthless for flight photography. The MIII was not around when either book was published. Not sure that I have stated the point in print so clearly but have mentioned it on IPTs and at seminars. Will try to remember to post something on that either in a Bulletin or on the blog.

[Leonard Malkin]

I did not say that 45-point with the MIII was worhtless, I said that it was worthless for flight photography. The MIII was not around when either book was published. Not sure that I have stated the point in print so clearly but have mentioned it on IPTs and at seminars. Will try to remember to post something on that either in a Bulletin or on the blog.

Sorry, I should have quoted you as saying the 45-points of the MkIII was worthless for BIF. My question is, why?

[Jim Neiger]

Sorry, I should have quoted you as saying the 45-points of the MkIII was worthless for BIF. My question is, why?

Leonard,

I answered this in my previous post. I'm pretty sure Artie will give the same answer.

[Leonard Malkin]

Leonard,

I answered this in my previous post. I'm pretty sure Artie will give the same answer.

I'm still a little confused. Artie suggests use all focus points for those of us who find it difficult to track with a single point. But why is the 45-point of the MkIII "worthless" for this compared to the MkII or the 9-point 40D?

[Alfred Forns]

Leonard I would not call the 45 point worthless but it is not as accurate as using the center point only. I rely on the center point for all my flight images.

I feel the Mk3 does not work as well using the 45 points as the previous model. In my case it hasn't affect me much since is that is not what I use.

I'm sure this is all confusing but you need to go back to the introduction of the Mk3 and the problems it had. I feel they have been resolve and is a fine performing camera.

[Doug Brown]

With that many focus points active, you are very likely to grab focus on something other than the bird's body Leonard. It could be a BG or FG element or it could be the wing. Center point focus is the way to go; it just takes practice. As mentioned above, hand holding should really help you get more keepers, and it's pretty easy with the 100-400. Start out focusing on distant slow-moving birds and gradually work your way into more challenging subjects.

[Arthur Morris]

Sorry, I should have quoted you as saying the 45-points of the MkIII was worthless for BIF. My question is, why?

Why? Because it does not work. It aquires focus only with great difficulty and when it does acquire, the focus is not accurate. And against a background other than sky, it is even worse.

The above only applies to the 1D MIII with flying birds.

[Tim Rucci]

With that many focus points active, you are very likely to grab focus on something other than the bird's body Leonard. It could be a BG or FG element or it could be the wing. Center point focus is the way to go; it just takes practice. As mentioned above, hand holding should really help you get more keepers, and it's pretty easy with the 100-400. Start out focusing on distant slow-moving birds and gradually work your way into more challenging subjects.

Even though I'm shooting with f2.8 glass, I still often stop down to f5.6 or even f8 for birds in flight, so as to provide more depth of field to eliminate some of this possible problem. Of course, if the camera locks on something in the background, all bets are off. But if it locks on a wing tip or some other unintended part of the bird, chances are you still get an acceptably sharp shot if your subject is far enough away. For close up subjects the DOF will not be much different.

I'm shooting with the Mk2N (I don't have a Mk3) and fortunately the Mk2N does not exhibit any of the focus problems that were reported on the Mk3's early on after it's release.

[Arthur Morris]

Again, I did much better with AAFPS with the Mark II series bodies than with the EOS 1-D MIII. That said, I have always hated ring of fire for flight--even with the MII series bodies, the system seemed to focus more accurately on birds on the edge of the ring than on birds centered in the ring of fire. And you are supposed to always start AF acquisition with the central sensor when using AAFPS....

[Roger Clark]

Art,
What is AAFPS? It is not in the acronym list.

With my 1D Mark II, I always use a single focus point and very which point I'm using for best composition. It has worked well for me. What really is the "sensitivity" difference with the center sensor? I understand it is a cross-type sensor, but that inherently does not necessarily change the accuracy (of course it does if your subject had contrast only in the direction that the AF sensor is not sensitive to). But my experience is that birds and animals in general have enough curves that this is not a problem. (I do understand how phase detect AF works.)

The Canon literature describes greater sensitivity for f/2.8 and faster optics, but for most birding we work at longer focal lengths and have slower f/stops, so this does not seem to be a factor. The canon literature also seems to indicate that the greater sensitivity is to lower light levels, not focus accuracy. If so, then using the center AF only would become important as light levels fall.

What hasn't been mentioned so far is that traditionally, the 1D bodies have a tighter specification on the circle of confusion and the AF system achieves a better focus as a result. For example, the AF is specified to be within X circle of confusion. X is smaller on 1D bodies. The specifics of this is in a Chuck Westfall white paper a few years ago. I wonder how the circle of confusion is defined these days between 1D and other bodies? But in either case, I have not seen any mention in Canon literature that the center point AF achieves a tighter more accurate focus than other sensors except for cases where cross type sensors help. But, for example, with an AF sensor on the eye, there is no difference in AF accuracy between a horizontal or vertical or cross-type AF sensor.

It seems that with people's experience with newer bodies, that the AF systems are changing and it would be nice to hear from Canon (Chuck?) what the specifics of those changes are so we photographers can make the best decisions in the field.