24mp v 40+mp post crop

[tonye]

Hi folks, both my cameras are 24mp, one DX the other FX, D5200 & D600. I notice that some members who have 40+mp cameras talk about close cropping in post and still have good shots to use with reduced pixels down to 24 and sometimes lower. My question is, is a heavily cropped picture as good as a shot with a 24mp and bigger lens. I can see a couple of major problem with cropping so much, depth of field and very critical focusing with a wider lens. Would love to hear other opinions on this before i go blowing a load of cash on a crazy ( for me ) upgrade. Thanks for looking, Tony.

 

[BF Hammer]

I think it is a bigger deal shooting wildlife, aircraft, and many astro subjects. Personally that is the direction I am working towards. But quality lenses is the higher priority to me, and a bigger difference maker for any subject. I have 2 or 3 lenses I want in the kit yet before I get a Z8, or more likely a 2nd generation model.

 

[Clovishound]

Here is an image I took last month with my Z8 and 180-600. It was taken handheld. The first image is the full frame, for reference.

The second is a heavier crop than I would ever do under normal conditions. You be the judge if the resolution is still there. The TIF file for the full sized is 130 MB (8256x5504), and the cropped is 5.6 MB(1133x1699). When viewing the TIF file on my monitor, vs this lower resolution JPG, I notice more detail and contrast in the TIF than this compressed, slighter smaller file for posting. I could probably edit this and add a little more contrast, texture and sharpness to bring it in line with the TIF file. Again, this is an extreme crop. It is far more than to the equivalent of a crop frame image at this focal length, and much more than most folks would ever normally crop, even with the higher resolution sensor. Full disclosure, this was shot under good conditions for resolution ( full late morning sun, 1/3000 sec with ISO 400 @F/6.3). A lower ISO and stopping down one stop or so would probably increase resolution a little bit.

For clarification, I do not use a shorter lens and then crop to get more reach, if a longer lens is available. I try and get the image as close to ideal in the camera (leaving a little extra for fine tuning in post), but often am further from my subject than I would like. This picture was taken at distance, and was as close as I could get with the longest lens I own. This is frequently an issue for wildlife photography, and we frequently wish for longer lenses, but have to use the lens we have in order to get the shot.

As to the concerns about depth of field, my understanding is that the depth of field is the same for a given focal length regardless of the sensor size. Critical focus may be an issue.

My experience has been going from a 24MP crop frame to a 24MP full frame to 46MP full frame. The 46MP images allow for far more cropping when cropping is needed. If something happened to my Z8, and all I could afford was a crop frame body, I would gladly go out and take pictures with it. I see tons of truly excellent images taken with crop frame cameras. I would, however, greatly miss the flexibility of the higher resolution images.

 

[tonye]

Great shot and now I understand why the 46MP is needed, especially for wildlife shots which can be challenging to say the least. Not my type of work, I mainly shoot landscapes and seascapes at very long exposure so not really of much use to my particular style especially now I have the D600 full frame in my arsenal. I also do street and portrait work with the fastest lenses i can get hold of and feel that with 46MP the outcome might be too sharp for my style.

Thanks to you both for the replies, I think my curiosity has been answered.

 

[Clovishound]

For most 24MP is plenty, even with a moderate amount of cropping. I agree that for the type of uses you listed as your genres, a high resolution sensor body is likely not needed. Perhaps, if you were making very large prints of your landscapes, it might be useful. There are some downsides to high resolution sensors. Cost, of course, and not just the camera. Most high rez cameras require a much more expensive CF Express card vs the cheaper SD. You also have to deal with the larger files. More storage space and longer download times are definitely downsides. If you are using F mount lenses, you also have to be careful about the lenses you purchase and use. Many of the F mount lenses do not have the resolution to take advantage of the sensor's capability. At one time Nikon put out a list of lenses that were sharp enough for their higher rez sensors. It's not that the other lenses wouldn't work, you just wouldn't be able to get the full resolution your camera was capable of when using them.

 

[tonye]

Thanks for the insight. I usually only go to 40inch x 20inch so only crop to fit and try to use the whole width and compose on back screen with this in mind. I'm on a limited budget and tend to not do much post work using SnapSeed which is good enough for my needs.

 

[nikonpup]

CHECK YOUR PHOTO EDITING SOFTWARE FOR A "Enhance OR Super Resolution" FEATURE.