What do you consider a reasonable crop?

[Fabs Forns]

With the advent of cameras with more megapixels, are the photographer's skills to be diminished, allowing for larger crops every time a get a new camera?
What do you require to be the minimum for an image to be a keeper, even considering that you may not ever print it.
Are you satisfied with a 1/4 of the frame image if it displays well in the web, or do you require a healthy chunk of the original capture to meet your standards?

[Ed Erkes]

I use a 12 MP camera. I prefer to keep cropping to a minimum, but often some minor cropping will improve composition. Personally, I probably wouldn't be happy with the image if I had to crop more than 40% away.

[Alfred Forns]

Having started with slide film you can imagine how I feel about it !! No question for just about all images there will be some cropping involved. A 50% would delete in camera for me and don't have many kept with 40% taken away.

... and it makes little difference the camera being used. Still take pride in being able to make the image. Just one example ... one of my proudest images is a full frame vertical purple martin .. with a good performing sensor you can duplicate my image using a 200 rather than 400 lens and taking a few steps back ... will even have much better dof !!!!!

[Flavio Rose]

Any crop that looks good is fine by me for Web and e-mail use. The eye is the ultimate quality tester for photography.

However, it also appears to me that crops in which fewer than four pixels of the original file correspond to one pixel of the Web-sized file will generally look inferior. As a techie I imagine that this is due to the fact that 4:1 reduction (2:1 linear) eliminates much of the blurring effect of Bayer interpolation. At 4:1, I think of greens as not being interpolated at all, and reds and blues as being interpolated only modestly. Thus, my rule of thumb is that for a 1024x683 Web-sized file, there should be at least 2048x1365 original pixels.

[arash_hazeghi]

Good points,

Always better to get as close as possible to the bird, will resolve more fine details and better subject to BG separation. For perched I like the bird to be ~80% of the frame with room around for composition. for flight I like the bird to be 50-70% of the frame, so the final crop with a bit of BG would be 70%-80%, most of my shots are this range...have had some that needed to add canvas!

Quality wise how much of a crop you can get away depends totally on the image sensor and performance of optics. With the 7D and 400 f/5.6 anything smaller than 60% of full frame was a kiss of death in terms of IQ, with 5DMKII and 500 I have made insane 10% crops (not for posting in Avian forum but for ETL and my own enjoyment of looking at them) at high ISO!!! they make nice sharp prints too (12X8), example in this thread http://www.birdphotographers.net/for...ad.php?t=64885

I also find that when the bird becomes too small in the frame it is hard for AF to track in flight, will often grab the BG so best is to get the bird as large as possible but without clipping the wings!

[Dan Brown]

I think that it really depends upon the usage for the image. For fine art prints, maybe a tiny crop for composition improvements. For Avian forum here on BPN, I try not to crop more than 30% off of the full frame.

For web/blog usage, with a 10+mp camera, you could really get away with a giant crop. I am currently involved in a couple things that very often require a giant crop (90%). One is a competition with several other California bird photographers to see whom can photograph the highest number of species of birds in CA in 2010! The only rules are that the species be on the CA checklist, the photo taken in CA in 2010 and the the bird be identifiable in the image! BTW, I am currently in the lead with 298 species! See my images here - http://naturestoc.smugmug.com/Nature...82317916_Qrgct
Most of the images are cropped about 50% but many are near not. I am up front about the crops also, which I think is a very good idea.

The other use that I would consider a giant crop is for a bird/subject rarity for a record. I am currently the photo editor of a bird club newsletter and we will accept any image where the bird is id'able and the rarier the species/record is, the crummy'er the acceptable image can be. Of course, we want the best image that we can get, but if the crop is giant and the bird is a mega rarity, it's good!

[arash_hazeghi]

Also another point that came to mind is that one of the "advantages" of getting the bird large in the frame is that you can get still get away if the image is slightly soft or noisy. since you will be downsampling a huge file to a small 1024pix JPEG, some of these errors will not be visible. here is an example of a photo from last year



7D 400 f/5.6 1/2000 sec f/7.1 SO 800. This was full frame and some canvas (5%) was added to the front, it looks great at this size and also at 8X12 print.

[arash_hazeghi]

but a closer look at 100% crop from head area shows that it was actually pretty soft :eek: Now if this was a tight crop it would have been an immediate delete.




For tight cropping photos need be razor sharp and clean when you view them at 100%, this is going to be more challenging with cameras with small pixels, so as long as wings are not clipped there is more room for technical imperfections when the bird is large in the frame.

[Doug Brown]

As long as the image looks good when sized for its intended purpose, I'll crop as heavily as I need to. If the image is sharp and the noise low, 25% of the original frame is easily doable.

[Dan Brown]

but a closer look at 100% crop from head area shows that it was actually pretty soft :eek: Now if this was a tight crop it would have been an immediate delete.




For tight cropping photos need be razor sharp and clean when you view them at 100%, this is going to be more challenging with cameras with small pixels, so as long as wings are not clipped there is more room for technical imperfections when the bird is large in the frame.

But, if it was a very endangered species or a first North American record for the species, I sure wouldn't delete it!!!

[Desmond Chan]

As long as the image looks good when sized for its intended purpose...

I tend to agree to this. I think this's a pragmagtic approach. After all, a photograph is for us to look at.

[allanrube]

I used a full frame with minimal cropping on my Florida vacation but use a 1.5 DX Nikon and crop more here in New England.

[Harshad Barve]

I would not like to crop more than 20% ( keeping 80% of original capture ).

[Lance Peters]

Interesting Discussion thats for sure.

I try and get as close as possible in camera to what I want my final image to be. That said a crop of some sort is often required for compositional purposes - Rare for me not to crop at all - even with a 800MM lens - very hard to get close enough here in OZ with wild birds - more the exception rather than the normal.
Hope to have some shots from the weekend though that will be close to full frame SOC.

Seems to be like a lot of things with Digital Photography - depends on your OWN personal ethics and what you intend to use the images for.

IMHO Though - for flight/action images a LOT EASIER with bigger crops - so it could be argued less SKILL also.

[Lance Peters]

Also so does that bring up the question of Full Frame Sensor VS a crop sensor??

IE: If I am shooting full frame and you are shooting crop factor - should I be allowed to crop to match the crop factor?? ALL other things being equal??

[Alfred Forns]

Hi Lance Most of the crops I'm talking about has to do with flight. A large crop will require less skill and/or produce many more keepers. Perhaps it would be fair to say the amount cropped?

[arash_hazeghi]

Also so does that bring up the question of Full Frame Sensor VS a crop sensor??

IE: If I am shooting full frame and you are shooting crop factor - should I be allowed to crop to match the crop factor?? ALL other things being equal??

Good point Lance, imagine same person, same skills shooting with different cameras, FF, 1.3X, 1.6X, 2X only difference is camera is doing the cropping for you :D In fact you can turn on DX cropping mode in Nikon FF so that the RAW file would be cropped in camera, although there is no difference between this and cropping in PS I think if you were to submit to a no-crop contest the former is acceptable and the latter not.

Different sensors have different pixel size and different area and the issue of cropping should be discussed with this fact in mind. For example If I shoot with a 7D from the same distance bird would be ~ 2.5 times larger in the frame so I may not require any cropping composition-wise, but with a 5D I might need to crop to get the same composition. My skills are the same, just the equipment used is different. At the end of the day if I can get better IQ and sharper image after cropping I guess it is legit, unless cropping is not allowed for the purpose. For film because all cameras were 35mm this was not an issue.

Very good discussion

[Lance Peters]

Good point Lance, imagine same person, same skills shooting with different cameras, FF, 1.3X, 1.6X, 2X only difference is camera is doing the cropping for you :D In fact you can turn on DX cropping mode in Nikon FF so that the RAW file would be cropped in camera, although there is no difference between this and cropping in PS I think if you were to submit to a no-crop contest the former is acceptable and the latter not.

Different sensors have different pixel size and different area and the issue of cropping should be discussed with this fact in mind. For example If I shoot with a 7D from the same distance bird would be ~ 2.5 times larger in the frame so I may not require any cropping composition-wise, but with a 5D I might need to crop to get the same composition. My skills are the same, just the equipment used is different. At the end of the day if I can get better IQ and sharper image after cropping I guess it is legit, unless cropping is not allowed for the purpose. For film because all cameras were 35mm this was not an issue.

Very good discussion

Arash - Exactly!! So the playing field is NEVER really level to begin with!!

[Alfred Forns]

Good point on the crop factor !!

I switch form Nikon back to Canon because the D3 did not have a crop factor. Enter an image in the BBC from a D3s that is large crop lets say 25% of the frame ... if they ask you for the raw since your image made it up the ladder as soon as they see the crop you will be out of the competition. Does that tell you anything?

You can argue till your face turns blue about how good the quality is etc but it won't make a difference.

[arash_hazeghi]

Arash - Exactly!! So the playing field is NEVER really level to begin with!!

The other issue for flight shots is the use of TC, I think we all know that the TC slows down AF quite a bit for flight shots compared to naked prime. So sometimes I deliberately take the TC off, with the TC the bird would be covering 90% of the frame but without would be 65% of the frame. But the chances of getting a sharp flight image with the TC is lower. This is not necessary a short coming of the photographer but a limitation of the equipment so I think in this case make sense to crop photos that are sharp rather than try to sharpen up the photos that are soft, if anything the former better shows the capability of the photographer.

But I think what Al was saying is that everything being equal it is not a good way to grab a shorter lens when a longer one is available or not get closer to the bird where possible, for the ease of tracking and make up for it by tightly cropping the files, sort of like cheating :D and I fully agree.

[Alfred Forns]

Great point on the use of a converter ... makes it even more difficult to track the bird, af is way slower but can be done !!! Keep that converter on and fill the frame.

For flight finding a bird with a 500/600 and converter is no easy task ... then you have to make a sharp image. Just takes skill and you can't get around it, if you want to crop I have no objections, I just want to know how much of the original was posted. It makes a difference !

One of my best images from Bosque was made with a 600 and 2X Had to crop very little (less than 10%) .. could have used a 1.4 X or no converter but would not have been happy with the result no matter how good the image quality. I went for the low percentage and won .. more often than no that is not the case but I have to try.

[arash_hazeghi]

Valid and good points Al,

I think some of the rules will change over time, as people become more familiar with digital. With different sensor sizes and etc. I remember Jimmie Niger mentioned he can no longer submit some of his older files because RAW is 8 mpixels only and minimum is now 10(?). But if it is sharp and clean sure can enlarge in PS and get great quality, no point in that minimum MP rule IMO.

For Nikon, the paradox is when you use the in camera DX mode, then the RAW file is cropped in camera and will generate a 5Mpixel NEF with 1.5X FOV. You can just submit that RAW file and I am sure it will be fine, it is a RAW directly recorded by camera. It is however exactly the same as cropping in PS!!!

BTW, filling the frame is sometimes cheating too :D like the example above, get a photo that is a bit soft and grainy then downsample to 1 mpixel and it looks good :) personally I like files that are sharp and clean when I view them at full size, even if they are cropped compared to bird that is full frame but soft and noisy, have found that will make better prints!

I agree, when possible, best is to get sharp AND large at the same time! Does require highest level of skill and should be a deciding factor in competition!

[Sabyasachi Patra]

I don't like to crop. If the subject is small in the frame, then anyone can do it. So composition suggestion means cropping the way you want in the computer.

It is not easy to move close and get frame filling image. There is a degree of skill involved in it. If the image is not sharp at 100%, then I delete it. One can argue that people in online forums can't make out. However, I can't live with the fact, because I can make out that it is soft. I make images for myself. So no cropping. Even, when I had only 300mm lens, I used to just watch a scene rather than shoot if the subject is far away. Ofcourse, if I see the proverbial snow man, then i will click even if I have a camera phone, to document the scene.

Cheers,
Sabyasachi

[Daniel Cadieux]

if you want to crop I have no objections, I just want to know how much of the original was posted. It makes a difference !

I feel this way too!! In my exif I always indicate how much of a crop my posted image is....there are many beginners that think it is easy to fill the frame, then are wondering how they can't do it consistently...only to later find out many of the images they were raving about were indeed heavy crops! Nothing wrong with it, just something most don't consider when taking up bird photography...

P.S. Anything on my website is at least 70% full frame, but most are at least 80-85%...just something I personally strive for. I have many larger crops for my personal usage and/or odd/rare/unusual behaviour stuff.

[John Chardine]

There are at least a couple trade-offs in getting close to your subject to reduce the need to crop:

1. Disturbance and unnatural behaviour in your subject
2. Depth of Field- much deeper at longer camera-subject distances. Here's an example where the whole head of the Chinstrap Penguin is in focus at f7.1 because I was at some distance from the subject:

http://www.birdphotographers.net/for...ight=chinstrap

Incidentally I've found the 1D mark IV to allow tighter crops than other cameras I have owned. This is presumably a combination of pixel density and pixel quality. To answer Fabs' question- no I don't think new cameras or longer lenses for that matter, are relaxing the demands on our skills as photographers. Does owning the superb 800mm f5.6 Canon lens make you any less of a photographer because you don't have to get as close to your subjects? I don't think so. And by the same token, nor does owning modern cameras that allow more extreme crops.

For those who say cropping in the camera in the only way to go, remember that cropping in the dark room was absolutely bread and butter to making a good print.

[Ken Watkins]

I can agree almost entirely with John's comments, certainly for the type of photography.

Disturbance is common place in particular for small antelope, almost everything else with the notable exception of Elephant and Lion are generally not easy to get close too unless extremely habituated ( Bonnet posing Cheetah in Mara).

Composing in camera is almost impossible unless you are on foot or can move around freely in your vehicle, neither of which is commonplace or in some cases sensible.

Going back to the original question I will crop as much as is necessary to get the image I would like to see, as long as I have sufficient IQ. (thankfully I have a 500mm lens):)

[Alfred Forns]

I think the basic crop question has to do with birds in flight more than anything else Ken.

A bird in flight made form only 25% of the image is much easier than one from 70% of the image .. HUGE difference in photographic skill. When one is posted and people marvel at the image I wonder if they know how big a crop it was?

This is not about getting close and disturbing wildlife etc. For wildlife is a totally different game !! Reasons for cropping have nothing to do with skill but circumstances !!

[Charles Glatzer]

I think the longer focal length should be used to make a smaller subject larger in the frame (as desired) from the closest subject to camera distance possible. Shooting subjects at greater distance with longer focal length lenses, and/or using converters will degrade the overall image quality. Atmospheric conditions and suspended particles such as dust, heat shimmer, snow, rain, etc will scatter, diffuse, reflect and more will render a soft non-detailed image regardless of lens IQ and a cameras pixel density. The more air between you and the subject the greater the loss in quality. Not withstanding the flattening effect and higher magnification adding to the problem.

Many times it is more prudent to shoot with a shorter lens making for a sharper image, than trying to maximize the subject size with the frame. The additional loss of light through converter use requires a decrease in shutter speed and/or increase in ISO, both can compromise image quality. The introduction of higher focal magnification also requires superior technical stabilization and typically less subject movement to render a sharper image than one taken at less focal length.

I try to compose images in camera to the best of my ability regardless of the camera so called crop factor in hand. That said I would crop in post-production to render an image as I see fit, providing the image maintains integrity for the intended output. A subject does not always have to be large in the frame for the image to be successful.

I do think it can be misleading to those trying to learn when posting a highly cropped image on line without disclosure.

Best,

Chas

[Ian Cassell]

Permit a newbie to join this conversation, possibly with my ignorance showing. Given 2 final post-processed images, one cropped and one full-frame, what difference does it make if there has been a significant crop as long as the final product reaches the artistic goal? I understand that a full-framed image requires increased technical skill , but does that really matter to the non-photographer viewer? Although I would disclose a crop to my fellow photographers if that is the norm, I don't see what difference that would possibly make to anyone else.

[Joel Eade]

"a picture is worth a thousand words"..........just require a totally unprocessed JPEG (sized for web only) to be posted with each final image.....everyone will quickly see what took place in camera as opposed to in computer.

Joel

[Charles Glatzer]

Permit a newbie to join this conversation, possibly with my ignorance showing. Given 2 final post-processed images, one cropped and one full-frame, what difference does it make if there has been a significant crop as long as the final product reaches the artistic goal? I understand that a full-framed image requires increased technical skill , but does that really matter to the non-photographer viewer? Although I would disclose a crop to my fellow photographers if that is the norm, I don't see what difference that would possibly make to anyone else.

As this is a learning forum the technical data provided/required is relevant to the making of the visual presentation. Other than that...if the image achieves your quality standard and artistic goals, go for it.

Chas

[Ian Cassell]

Chas, that makes perfect sense to me. For the benefit of education, of course it matters how an image was made. I thought the implication here was, however, that one way is the ' only right way' to get a desired result and I was going to humbly disagree with that philosophy.

[Daniel Cadieux]

Agree with Chas. Another reason for disclosure (especially highy cropped images) is that many beginners will by a large lens and eagerly head out to their favorite haunts to fill every frame with every bird they see...only to realize how deceptively small a bird may appear, even with a huge lens attached to thir camera.

I remember buying my first "real" birding lens...a 300mm one. Man, I was sure the small songbird 20-30 feet away was going to be huge in the frame even with what I saw in the viewfinder!! Imagine my dissapointment when "chimping" my first Chickadee "dot" in the frame!!:eek::o At least with disclosure you are forwarned that there may be more to it than pointing the lens at every bird within sight:).

[Ian Cassell]

I remember buying my first "real" birding lens...a 300mm one. Man, I was sure the small songbird 20-30 feet away was going to be huge in the frame even with what I saw in the viewfinder!! Imagine my dissapointment when "chimping" my first Chickadee "dot" in the frame!!:eek::o At least with disclosure you are forwarned that there may be more to it than pointing the lens at every bird within sight:).

Oh boy, ain't that the truth! I experienced the same when I bought my 100-300. It figured into my recent decision to buy the 400/5.6. I know this will be a shorter FL than my 300 + 1.4TC, but I no longer suffer any illusions. I had the occasion to use a 500/4 + 1.4X a few weeks ago and, even there, wished I had longer ... At least improving field-craft is cheaper than investing in new glass!

[Kaustubh Deshpande]

Interesting discussion. I personally dont like to crop a lot. On 40D files, I like to keep at least 70% of the pixels.

Even with the better files of the better cameras, one should consider the DOF and its effect on the BG. Cropping-and-resize-for-web can make a bird shot with 400mm lens look like it was taken by 800mm lens but the BG can give it away....and ruin it actually. I guess when one is shooting flying birds with sky as the BG....or any situation where BG is very distant, this is not that big an issue. Arash has demonstrated that many times. But with birds-in-foliage shots, one cannot get away by cropping large even if the files are of superior quality. When one is shooting from far with the BG close to the bird, in most situations, cropping is not going to make the shot look great. Unless one wants to blur BG in photoshop. Just my 2 cents.

If bird is going to be small in the frame( common scenario for me unfortunately:-), I try to crop for a bird-in-habitat shot instead of going for a huge crop. 40D files are not very croppable IMO.

[arash_hazeghi]

Interesting discussion. I personally dont like to crop a lot. On 40D files, I like to keep at least 70% of the pixels.

Even with the better files of the better cameras, one should consider the DOF and its effect on the BG. Cropping-and-resize-for-web can make a bird shot with 400mm lens look like it was taken by 800mm lens but the BG can give it away....and ruin it actually. I guess when one is shooting flying birds with sky as the BG....or any situation where BG is very distant, this is not that big an issue. Arash has demonstrated that many times. But with birds-in-foliage shots, one cannot get away by cropping large even if the files are of superior quality. When one is shooting from far with the BG close to the bird, in most situations, cropping is not going to make the shot look great. Unless one wants to blur BG in photoshop. Just my 2 cents.

If bird is going to be small in the frame( common scenario for me unfortunately:-), I try to crop for a bird-in-habitat shot instead of going for a huge crop. 40D files are not very croppable IMO.

Kaustubh, using a longer lens only helps with BG separation if aperture is not changed, for example there is no benefit in terms of BG separation when you add a TC (500mm f/4 vs 700mm f/5.6) or when going from 600mm f/4 to 800mm f/5.6. Most of the time if bird is so close to BG that for example it will not make an appealing shot with 600mm, most likely it won't with the 800mm either, because the bokeh will come out busy and harsh anyway.

[Kaustubh Deshpande]

Arash, I think you misunderstood me. What I am saying is cropping can give you magnification and field-of-view of longer lens but not the DOF.

I can take (a) a shot with 400mm at f/5.6 with 20mp camera and then crop it 50% in post. Or (b) take that shot with 800 mm at f/5.6 with 10mp camera and not crop it. assume same sensor size in both. In both, the bird is of same size in frame. But (b) is going to have better BG blur and will look better. discounting all other things like lens quality, noise etc. If BG is sky, it doesn't matter as much but if the BG is foliage that is close to the bird, it matters a lot.

Dont get me wrong....I am not saying cropping is not a good idea. Just depends on the situation along with the camera.

[Charles Glatzer]

Kaustubh, using a longer lens only helps with BG separation if aperture is not changed, for example there is no benefit in terms of BG separation when you add a TC (500mm f/4 vs 700mm f/5.6) or when going from 600mm f/4 to 800mm f/5.6. Most of the time if bird is so close to BG that for example it will not make an appealing shot with 600mm, most likely it won't with the 800mm either, because the bokeh will come out busy and harsh anyway.

Longer focal length will provide more apparent image compression between the subject and background.

Chas

[arash_hazeghi]

Longer focal length will provide more apparent image compression between the subject and background.

Chas

Not if the aperture is smaller

Dof is function of focus distance, aperture and focal length.

[arash_hazeghi]

Arash, I think you misunderstood me. What I am saying is cropping can give you magnification and field-of-view of longer lens but not the DOF.

I can take (a) a shot with 400mm at f/5.6 with 20mp camera and then crop it 50% in post. Or (b) take that shot with 800 mm at f/5.6 with 10mp camera and not crop it. assume same sensor size in both. In both, the bird is of same size in frame. But (b) is going to have better BG blur and will look better. discounting all other things like lens quality, noise etc. If BG is sky, it doesn't matter as much but if the BG is foliage that is close to the bird, it matters a lot.

Dont get me wrong....I am not saying cropping is not a good idea. Just depends on the situation along with the camera.

Going from 400 to 800 is a factor of 2 in linear FOV but a factor of 4 in area, so you would have to crop 25% ( 5 mpixel) to get the 800 FOV.

But you missed my point, if you have a 500 and need shallow DOF you will shoot at f/4, when you add the TC you will be shooting at f/5.6, there is no advantage here in BG separation because DOF is identical. So yes, if you go from 500mm to 600mm both at f/4 you will get shallower DOF, but in my experience the little you gain in terms of shallow dof does not affect the final appearance of the photograph by a noticeable margin. I am interested to see side by side examples taken with 500mm and 600mm at the same aperture in which for 500mm BG is too close and distracting but soft and creamy in 600mm.

There is no question between hypothetical case of 400mm f/5.6 vs 800mm f/5.6 primes, who would use a 400mm over 800mm and then crop to 25% of the frame any way? not a realistic scenario IMO. But the example of TC is a realistic one :)


Best

[Kaustubh Deshpande]

Arash, thx for correcting me on the numbers.

[Ed Cordes]

Well, I voted 40% of original. However While I would prefer not to crop at all, I do find with the newer cameras I can crop a lot more and still get a good image as long as the original is sharp to begin with. That said anything less than 40% of the original seems to break down even with the high MP and careful processing. Yea, they look OK on the web, but I am concerned about the print quality at about at least 8 X 12 or so.

I have printed a larger crop of an unusual behavior or a first time species for me to illustrate the experience. However, it is not pro quality, just illustration.

[Kaustubh Deshpande]

But you missed my point, if you have a 500 and need shallow DOF you will shoot at f/4, when you add the TC you will be shooting at f/5.6, there is no advantage here in BG separation because DOF is identical.

Best

agreed on that. didn't miss that point. Sorry if you thought that way.

[arash_hazeghi]

Well, I voted 40% of original. However While I would prefer not to crop at all, I do find with the newer cameras I can crop a lot more and still get a good image as long as the original is sharp to begin with. That said anything less than 40% of the original seems to break down even with the high MP and careful processing. Yea, they look OK on the web, but I am concerned about the print quality at about at least 8 X 12 or so.

I have printed a larger crop of an unusual behavior or a first time species for me to illustrate the experience. However, it is not pro quality, just illustration.

You should have 0 problem producing fine art exhibit quality 8X12 prints from 40% crops of a camera like 1DMKIV or 5D, unless the original is soft, noisy or RAW conversion is poor. A 40% crop of a 5D is 8.2 Mpixels, as big as a file from 20D, I have made at least 50 high quality prints with the 20D when it was my main camera. Several prints that I made were 18X12 for a client and they are still hanging on the wall in their office :)

[Charles Glatzer]

Not if the aperture is smaller

Dof is function of focus distance, aperture and focal length.

Agree about DOF. But, when using more focal length to shoot smaller subjects at greater distance rather than getting closer to the subject to increase magnification you are shooting through more atmosphere. The greater the subject is from the camera the more particulate matter in suspension, and subsequent lighting anomalies resulting in a softer image...with aperture remaining the same.

My point being bigger is not always better. Getting closer (when possible) with a shorter lens will quite often yield sharper results, you can then use aperture to control DOF.

Chas

[arash_hazeghi]

Agree about DOF. But, when using more focal length to shoot smaller subjects at greater distance rather than getting closer to the subject to increase magnification you are shooting through more atmosphere. The greater the subject is from the camera the more particulate matter in suspension, and subsequent lighting anomalies resulting in a softer image...with aperture remaining the same.

My point being bigger is not always better. Getting closer (when possible) with a shorter lens will quite often yield sharper results, you can then use aperture to control DOF.

Chas

Agreed Chas, getting closer much better than adding a TC or using a camera with crammed pixels. A smaller tack sharp bird is much better than a big but soft bird (like the RTH photo above). I can always get better results when the bird is tack sharp even if cropping tighter.

Best

[John Chardine]

Agree about DOF. But, when using more focal length to shoot smaller subjects at greater distance rather than getting closer to the subject to increase magnification you are shooting through more atmosphere. The greater the subject is from the camera the more particulate matter in suspension, and subsequent lighting anomalies resulting in a softer image...with aperture remaining the same.

My point being bigger is not always better. Getting closer (when possible) with a shorter lens will quite often yield sharper results, you can then use aperture to control DOF.

Chas

Chas- there is no science I am aware to support this, except in special circumstances. One of these would be when you have small scale variation in the density of air, AKA heat shimmer- the more shimmering air you shoot through, the worse the problem. As for particulates causing soft images I don't see the cause and effect relationship. You will get a reduction in contrast as a result of light being scattered by the particulates, but I don't think image softeness per se will result, at least not at the distances we are shooting at. All this is academic though. The proof of the pudding is in the quality of images made with super-tele lenses, all of which force you to shoot through more air than shorter lenses. First, these lenses produce excellent results as evidenced here at BPN, and second, on average, the 600 and 800 mm lenses produce just as excellent a result as the 300 and 400 mm lenses, again as evidenced here at BPN.

[Alfred Forns]

Hi John Could not agree with you more !!!!

All being equal I will continue my philosophy of getting a good size of bird in my frame so after cropping for proportion from to bottom etc I still have 60% or more of the frame left. Will place a teleconverter to achieve those results when the bird gets to be too small in frame.... does increase the difficulty since the af is slower and the magnification higher but the quality won't be down.

I guess I can not take pride in being content with filling just 25% of the frame and being happy with it. There is no right or wrong here just different thinking and comfort zones.

Perhaps I endorse the Willy Mays baseball philosophy ..... when they throw the ball I hit it, when they hit I catch it !! Can win a lot of games like that !!!!

[Charles Glatzer]

Chas- there is no science I am aware to support this, except in special circumstances. One of these would be when you have small scale variation in the density of air, AKA heat shimmer- the more shimmering air you shoot through, the worse the problem. As for particulates causing soft images I don't see the cause and effect relationship. You will get a reduction in contrast as a result of light being scattered by the particulates, but I don't think image softeness per se will result, at least not at the distances we are shooting at. All this is academic though. The proof of the pudding is in the quality of images made with super-tele lenses, all of which force you to shoot through more air than shorter lenses. First, these lenses produce excellent results as evidenced here at BPN, and second, on average, the 600 and 800 mm lenses produce just as excellent a result as the 300 and 400 mm lenses, again as evidenced here at BPN.

Hello John,

As evidenced in field.

Particulate matter such as snow will quickly degrade an image as the distance to the subject increases, rain has a similar effect, as does blowing sand on a Falkland beach, and dust in high desert. This is imply because there are more flakes, drops, etc between the glass and camera at greater distance to obscure the subject.

This effect was again illustrated recently in YNP while shooting an osprey on a rock top nest. The air was still a bit humid just after a brief rain, images taken under cloud cover appeared sharp with fine detail, while those taken in sunlight did not. The sun light shining off the droplets degraded image quality. Images were taken with a Nikon 600 and Canon 800, both rendering similarly.

Bottom line... the more inclement the weather the shorter the focal length I use. At times this means taking a more environmental approach to my image making, with the subject being smaller in the frame, unless I can more closely approach the subject.

Best,

Chas

[Charles Glatzer]

Hi John Could not agree with you more !!!!

All being equal I will continue my philosophy of getting a good size of bird in my frame so after cropping for proportion from to bottom etc I still have 60% or more of the frame left. Will place a teleconverter to achieve those results when the bird gets to be too small in frame.... does increase the difficulty since the af is slower and the magnification higher but the quality won't be down.

I guess I can not take pride in being content with filling just 25% of the frame and being happy with it. There is no right or wrong here just different thinking and comfort zones.

Perhaps I endorse the Willy Mays baseball philosophy ..... when they throw the ball I hit it, when they hit I catch it !! Can win a lot of games like that !!!!

Al,

We are in agreement that it is always best to try to make the subject as large as desired in-camera, rather than in postproduction via cropping. We all have different standards of image quality, I shoot mostly with 1Ds MIII bodies filling the frame as I see fit. However, if someone feels that a 50% crop suffices for there purpose who am I to claim differently. Of course I will try my best to show the maker that there is a difference in quality, but it is ultimately up to the photogs to decide for themselves.

I believe many photog's self impose restrictions that stifle creative growth. Don't shoot above ISO 400, or at mid-day, always point your shadow at the subject, never use flash, never crop, use Av/Tv only, no converters, etc. Many only use a zoom as an in-camera cropping tool, as they were not taught differently. I only offer suggestions, not definitive, non-of which should be taken as gospel. I try to simply add crayons to the artists box, ultimately it is up to them to draw the picture as sublime or creative as they see fit.

Warm Regards,

Chas