Exposure?

[Andre Pretorius]

Techs:
Nikon D3S+ Nikon 600F4
ISO 640
1/250 @6,3
Fill flash? used

Please do not scold me for posting this here, I needed an image to put my questions forward, I need it to be answered by my experienced, well learned friends.
My exposure questions:
When shooting a darker subject against a bright background, like this bateleur, how does one correctly expose? I use spot metering, the subject will be exposed correctly, but the BG will be blown.
Does one expose TTR when using spot, or only for Centre-weighted and Matrix?
I was trying all options, in this image (I chose the worst of the series, to make a point) I even tried TTL flash.
Will attach a jpg copy of the RAW.
When shooting BIF, I never could get sharp images with the heavy 600 rig, decided to go with manual with auto ISO and spot metering. My thinking- I need say 1/3200 to freeze action, would like f6,3 or more; for bigger DOF, do not know if bird is going to brighter or darker areas. I was told by many much more experienced photographers NOT to go this route, but why? I got more crisp images using this technique.
And lastly- does one use 3D focus tracking for BIF?

I have tried the web with numerous forums, tutorials etc- I can not get the answers I needed.

I have learned more on BPN in the last couple of months than in the previous 10 years:S3:.

[Andre Pretorius]

The Original:

[arash_hazeghi]

Hi Andre,

you asked several questions in one:

1) your image is badly blown up. The color tones are lost and that's why you had to convert to B&W. The issue is spot meter, I never use it for bird photography because it is erratic depending where it falls (a bird is not a uniform-tone subject). You will end up with frames like the above. for BIF it only gets worse because if it falls off the bird it will read the BG, sky etc. The most reliable method for metering birds is manual exposure IMO. I always use it and in the past 7 years I have missed less than 10 frames because of exposure error in all these years. That's how solid it is. As the bird moves against different BG's the meter will be fooled and pick up random readings, resulting in heavy overexposure when the bird flies against dark BG and extreme underexposure when it flies against a bright BG. Try to learn how to use manual exposure.

2) hand holding, the Nikon 600 VR is a heavy lens and its heavier in the front. Not everyone can handhold it. Unfortunately it is a limitation of the Nikon system. I suggest you use a 500VR which is perfectly hand holdable for anyone. Handhold technique requires lots of practice and field advice from a professional skilled in the art. It is hard to learn it by just reading online. The same way it is difficult to learn to become a good swimmer by just reading books. You need hands-on coaching in the field. Consider taking a workshop if you really wish to learn it

3) 3D AF does not work well for BIF. No automatic AF selection mode works for an erratic subject such as BIF. The best BIF shots are those taken against varied BG's and in those situations the camera will just lock on the BG if you let it pick the AF point. Use center point or center point plus a limited number of expansion points. keep the bird centered while tracking.


hope this helps

[Andre Pretorius]

Thank you Arash, I would love to attend a workshop/ have personal training, my geographical position makes it impossible. Will be trial and error?

Appreciate your input tremendously.

[Daniel Cadieux]

Yes, manual exposure is the way to go, and it is much easier than it sounds. Take a test image, check the histogram, then if needed adjust to get some data into the fifth column (expose TTR). You can also use the "blinkies" feature if your camera has it (where blown highlights "blink" on and off when viewing on the camera's LCD). In time you will know pretty much the general ball-park setting you need and adjusting is quickly done in manual.

P.S. I never use spot (and do not see the need for bird photography), but all modes will work when using manual exposure and checking the histogram.

[Tony Whitehead]

Andre, I agree with Arash and Dan regarding manual exposure for BIF as it eliminates changes to exposure caused by tracking the bird against varying backgrounds.
The thing that seems to be troubling you is how to determine the “correct” exposure which is what you would then have to set manually. In-camera meters are reflective meters – meaning that they measure the light reflected from your subject. The different metering modes (Matrix, centre-weighted, spot) measure the scene differently. All of them return an exposure reading to render an 18% grey tone. A hand-held incident light meter measures the light falling on the scene and can be useful to determine exposure without the confusion of having to add or subtract light depending on the reflectivity of the subject. Using your in-camera meter to read off a 18% reflectance subject (green grass, deep blue sky) can similarly give a useful starting point.
Matrix metering (Evaluative if Canon) looks at the whole scene and based on a number of factors including focus point applies an algorithm to determine an exposure value to suit what it assumes is the type of scene you are photographing. In this case I suspect it would have given an exposure that would have slightly over exposed the sky and under exposed the Bataleur. As a guess on a D3s I suspect Matrix +0.7 would have been close
Centre weighted measures the central area of the frame and returns an exposure value to render this as an 18% grey. With your image I suspect it would have returned a similar result to matrix as the centre of the image contains dark bird and bright sky. As a guess on a D3s I suspect Centre weighted +0.3 would have given a reasonable exposure.
Spot metering (Partial metering if Canon) allows you to measure just the breast of the bird and determine an exposure to render this as an 18% grey tone. In this case the birds plumage is probably a bit darker than 18% grey so the meter reading would over expose slightly (if the bird was black it would overexpose a lot to make the black look 18% grey and if the bird was white it would underexpose a lot to make the bird look the same 18% grey). My guess on a D3s is that spot metering the breast -0,3-0.7 would have given a reasonable exposure. It is a matter of understanding what you are measuring and then how you want it to appear – to make the black bird look black you would meter and then reduce the exposure by 1.5-2 stops and with the white bird increase the exposure by 1.5-2 stops to render the bird as clean white. The histogram can be useful to determine where you are but can be misleading in some situations. With this image if you only looked at the bird and could get a histogram of only the bird I suspect you would have a fairly nicely ETTR histogram and in a raw processor I think you could pull a reasonable image of the bird from this exposure. If you look at the whole image including the sky I imagine that you have a lot of blocked off highlights/blinkies as the bright sky is very over-exposed/blown.
This brings us to the issue of dynamic range – how many levels of brightness can be adequately recorded on a sensor. Our eyes (with their associated computer) can appreciate a wide variety of brightness and retain detail while a camera sensor can only record a limited range. This is improving over time and I have been amazed at the range that can be pulled from a D800 file but we still need to decide which part of the image we want to expose for to have it rendered cleanly. If you want a sky with detail and a dark bird with detail you can try and open the darker areas in post-processing but will have to accept some noise, or you need to add light to the dark area with fill flash (this is constrained by your distance for the subject and overall scene brightness – in bright scenes such as this you need to be quite close, even with a Better Beamer, as you are stacking 4-8 AA batteries
against a hydrogen fusion device which is a bit like bringing a knife to a gunfight despite the inverse square law) – if you are using a high speed sync for the flash your range drops to meters. The other option to capture a wider range of tone is to use an HDR technique with multiple exposures which is seldom viable with mobile subjects but in this case you could mask a sky from a frame taken with less exposure than the frame which captures the bird optimally.
There is a bit of trial and error that our LCDs and histograms can help with but only once you’ve got into the ballpark by understanding what you are measuring and how to apply that to achieve the effect you want. If I were trying to capture an image of this bird against a detailed sky I would have exposed this image a lot less than you did (expecting few blinkies and no cut-off on the right of the histogram). If I were trying to make a high key image against a white sky I would have probably exposed to within 0.5 stop of what you did (but with no flash) and expected the whole sky blinking back at me and a big cut off on the right of the histogram representing the blown sky that I was wanting to render as white.
I hope that this is helpful and that I haven't missed the point of your question.

[Carl Walker]

Hi Andre. I am in the same boat as you in trying to master M mode for shooting as I can see that it is successful and the way to go. Surprisingly I have had others tell me to use auto iso as well and up until I started reading material on BPN and others but with the negativity based on this I stopped. I was also not able to process those very high iso images successfully. The same source, when I first started using digital a year ago, also mentioned that I should shoot at - 1 ev and work from there. I have since learnt with good advice to ETTR and have been way more successful with images over the past few months.

My problem is ( practice practice I know) trying to set the exposure compensation on the fly to adjust to changes in light or varying backgrounds. If the birds in flight I tend to keep my designated ss and only adjust the ss if I feel that I can do that( to compensate for exposure) on the index wheel as my thumb is on the rear/back focus button - my middle finger is on shutter release button so that i can access index dial easily with the index finger. If I have time it is different - I then will change aperture with the thumb wheel if necessary. Hope I am not stating the obvious here. I will persist with this until I get it right.

Thanks Arash and especially Tony for your info on metering.

[Andre Pretorius]

Thank you Daniel and Tony!
Tony, I have read your reply(tutorial), printed it, will have to read it MANY times to fully grasp it. I really appreciate the time and effort you have put in to this reply, forever in your debt.
Regards
Andre

[Mervyn Marsh]

Hey all, great feedback around using manual for black and white birds, anyway I like how this photo turned out in black and white and think it looks interesting, sometimes you get cooler photos by mistake :)

Cheers,

Merv

[Jim Neiger]

Andre,

What follows is a snip from a tutorial I wrote in an old thread. It describes the method I use for determining proper exposures when working in manual exposure mode. I hope it helps. If you would like a very detailed tutorial on this, you can find it in my e-book which may be purchased from BAA.

---------------------------------------

Manual Exposure Mode:
The first thing to learn is to use manual exposure
mode. Manual exposure mode is virtualy a requirement when photographing birds in
flight. The reason for this is the likelyhood of changing backgrounds. If you
use any of the automatic exposure modes, the camera will decide an exposure for
you. When a bird flies across changing bgs, the camera may calculate a different
exposure for each frame depending on the bg. If the bird is in the same light
all during the flight, then we want the one correct exposure for the bird, not a
bunch of different exposures all but one of which will be wrong. The only way to
achieve this is to use manual exposure mode.

Substitute metereing
method:
To arrive at a correct exposure I use a method I developed that I
refer to as substitute metering. By substitute metering I mean using something
other than the subject to meter on. I don't usualy meter on the subject bird
because the subject bird is often not present at the time I am determining the
exposure. Instead, I use a constant in the environment. Something that is almost
always readily available. In Florida I use bright green vegetation that is
almost always present. When I was in Alaska in winter, I used snow. The
important thing is that it is readily available and something you are familiar
with. The first step is to fill the frame with the constant in the same light
that you anticipate your subject being in. I usualy choose constant that is in
direct light. (In the direction my shadow is pointing) Then I adjust my settings
so that the meter scale reads zero while filling the frame with the constant. I
use full frame EV metering so that my reading is not thrown off too much by
small areas of shadow or bright highlight within the constant. It's too easy to
hit a dark or bright spot with spot metering, so I don't use it. Step 2 is to
compare the constant to the subject. This is a two part process. The first part
is common sense. Determine if the subject is darker or lighter than the
constant. This tells you if you need to increase or decrease your exposure. If
the subject is darker, you need to increase exposure. If the subject is
brighter, then you need to decrease exposure. The second part is to determine
how much to increase or decrease exposure. This part is based on experience. If
you do not have a relevant experience to call on, then you must guess. After you
guess and make an exposure you can evaluate how you have done and then adjust if
needed. This is how you build experiences to draw on in the future. Try to
remember your experiences. This is sort of like keeping a database in your head.
After doing this for a while, you will have enough experience to know how much
to increase or decrease your exposure in pretty much any situation. One thing to
consider is the intensity of the light and its effect on exposure. For example:
If you use a middle tone green vegetation as a constant and you want to
photograph a white Great Egret, common sense tells us that we need to decrease
our exposure to avoid blowing out the white egret. We need to draw on experience
to determine how much to decrease exposure. If its just after sunrise and the
light is very soft, the amount to decrease exposure may be only 1/3 of a stop.
If we photograph the same bird at high noon, the amount we need to decrease
exposure by will likely be as much as 2 stops. You can see from the example how
much the intensity of the light can effect compensation amounts. Once you have
built a solid database of experiences in your head and you have become
consistant in getting correect exposures, you can easily do things like adjust
exposure quickly on the fly when the subject or light changes. This can be done
by counting clicks on the adjustment wheels and without repeating the metering
process.

I hope this helps people get started using manual exposure mode
for photographing birds in flight. I use manual mode about 99% of the time.
There are many benefits of using manual mode. Manual mode will make you a better
photographer in many ways, but it all revolves around increasing your
understanding of light and its effect on your photography.

[Andre Pretorius]

Thank you Jim, have read your tutorial many times before, still trying to have the guts to to full manual…..Will try it in the Kalahari on next trip.

[Kaido Rummel]

These are some great tutorials. I have also been afraid to go full Manual while on the field. In these days the RAWs can forgive a lot but the BIF photos have always been a problem. After reading the threads here it gave me courage to start trying the scary M-mode. I am sure that in the beginning it might mean some missed shots or failed exposures but in the long run it probably will help me make better photos. And that's what counts. Thank you Tim and Tony for the detailed reviews!

[Loi Nguyen]

Don't be so scare of the M mode. Unlike many people on this a Forum with vast experience, I'm relatively new to photography. Other than cheap P&S, I didn't pick up my first DSLR camera until about 2 years ago. I was scared of the M mode as well until I met Kerry Perkins who showed me how easy it is to shoot in M mode about 1 year ago. Yes, I do miss shots because I am slow to change exposure when something happens quickly - a dark bird flies in while the setting is for white bird, for example - but the shots I get to keep because I expose correctly far far outnumber the many shots that I had before without M mode. Jim's tutorial is really good, but Daniel's suggestion for using trial and error and blinkies is invaluable. Just use it and your exposure will improve. It's not that complicated. Loi