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 p.4 #20 · Pixel density and motion blur | |
Photon wrote:
Nill, I don't think you're confused, I think some people are confusing the issue.
For example, I would like to see an example of a sports image shot at 1/1000 sec on film, printed at 24x36, and scanned at sufficient res to match a 1D4 image at 100% (or of course just compare two large prints). I didn't shoot sports in my film days, unless you count a few college basketball shots, but I'm skeptical of some of the claims I'm seeing here. That is, I really think that if we are considering a particular fast action moment, shooting from a particular spot, and framing a particular way, motion blur will depend only on shutter speed. Motion blur may be masked or made apparent by other aspects of image sharpness, which will be affected by a host of factors (all of them probably mentioned in one post or another), but that one characteristic (motion blur) should not change with sensor resolution, sensor size, film to digital, or for that matter even lens resolution. Just keep in mind that when everything else that can yield a higher resolution, sharper image has been done, the effect of any motion blur will be maximized....Show more →
I believe that most of the incorrect judgments being by people when they are comparing two cameras with significantly different numbers of pixels or different pixel densities come as the result making the same error when doing that comparison. And that error is to compare images from the two cameras at 100%. Doing so will result in incorrect conclusions about image sharpness, noise, and image quality in general.
Jens Dresling may well be an excellent photographer, but I would guess that he is making that same mistake. If you compare an image taken with a 1D Mark II at 100% to an image taken with a 1D Mark IV at 100%, you are, in essence, magnifying a portion of the 1D Mark IV image twice as much as you are magnifying the comparable portion of the the 1D Mark II image. And you are, thus, also magnifying any motion blur (or camera shake) twice as much also. Doing so, therefore, might lead one to the incorrect conclusion that, for the same sized print, you needed to double your shutter speed when using the 1D Mark IV. As most who have contributed to this thread earlier concluded, that simply is not the case. The more accurate comparison would be to compare the 1D Mark II image at 100% to a 1D Mark IV image at 50%. Doing that would be using comparable portions of the images from both cameras. And I'm confident that the result of doing so would be that both images would show similar amounts of motion blur. As stated by several earlier, if you are planning to print the 1D Mark IV image at twice the size of the 1D Mark II image (or crop it twice as deeply), then, yes, you will need faster shutter speeds to compensate for the greater magnification of the motion blur in the larger print (or more heavily cropped image), but, for the same size prints or the same amount of cropping, the same shutter speeds should be sufficient for both cameras.
Not only does this make logical sense, but I've used a 1D Mark II and am now using a 1D Mark IV. I've used a 40D, and I'm now using a 7D. Having taken thousands of pictures with each of these cameras, I'm absolutely certain that, for the same sized print output (or the same amount of cropping), the same shutter speeds will be needed with the 1D Mark II as the 1D Mark IV or with the 40D and 7D. On the other hand, if I know that I am going to want to be able to print larger or that I'm going to have to crop more, I consciously seek to use higher shutter speeds to compensate for the fact that I'm going to be enlarging the image more and, therefore, also magnifying blur to a greater extent.
As long as people insist on comparing cameras with different pixel counts at 100%, no matter how good the actual images from the cameras with more pixels may look, those people are never going to be happy with the newer cameras with more pixels, and they should probably be using a D30 or a 1D. Even though the overall image won't be as good as that from a 7D or a 1D Mark IV, those 100% crops from the D30 or 1D will look great, and they will be able to continue to believe that the D30 or 1D produces better images that are sharper, have less noise, require slower shutter speeds, etc.
Les
Edited on Mar 13, 2010 at 10:01 PM · View previous versions
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