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brainiac
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 p.1 #1 · 5DmkII less sharp than 5D! | |
I want to pre-empt an inevitable controversy.
BE WARNED, there is certainly going to be a lot of gnashing of teeth and wailing about how noisy and unsharp the 5DmkII is after it ships, and people start comparing 100% crops with their old 5D's. Ignore it. This will only happen because people will fail to uprez their 5D files to 21 megapixel before comparing 100% crops.
Even reviewers like DPReview and Luminous Landscape routinely make this methodological error when comparing cameras.
There is a simple way to see what your new files are really like: uprez the 5D file to 21 megapixels, and then compare 100% crops. That way the images are magnified to the same size, and the comparison is fair. Contrary to popular belief, uprezzing does not turn a unicorn into a pantomime dromedary.
Lenses like the 24-105 are unlikely to take full advantage of the 21 megapixel sensor. Depending on the aperture, some significant part of the frame will be resolved at less than 21 megapixel resolution. How much that matters to you depends on what kind of photography you want to do.
I have been using the 1Ds3 since December, and although I no longer own a 24-105, I use a Zeiss 24-85 N which is quite similar, and with quite a few other lenses also I have noticed that they limit sharpness, and require more sharpening in post. However, some lenses really milk the sensor and require no abnormal sharpening, so it's definitely not the AA filter.
Primes generally give good results. Expect to use a 17-40 at f8 or f11, with DPP lens aberration correction, to get optimal results. Even then, you will see some loss of sharpness towards the corners. Here's an example:
http://cyberphotographer.com/1ds3/stevestevemarc_lowrez.jpg
unscaled crops:
http://cyberphotographer.com/1ds3/stevestevemarc_gloves.jpg
extreme bottom right corner:
http://cyberphotographer.com/1ds3/stevestevemarc_bottomright.jpg
It is VERY IMPORTANT TO REMEMBER THAT WHEN YOU EXAMINE 100% CROPS FROM A 21 MEGAPIXEL CAMERA YOU ARE VIEWING THE IMAGE AT SIGNIFICANTLY HIGHER MAGNIFICATION THAN YOU ARE USED TO. This means that although the lens defects and noise are more visible in 100% crops, the print is still better than you were getting from your 12 megapixel camera. A 100% crop of a 21 megapixel file is a much higher level of scrutiny. The per pixel noise in a 21 megapixel file doesn't need to be as good as the noise in a 12 megapixel file in order for the 21 megapixel file to equal or surpass the lesser file's noise footprint.
In other words, it is very important to understand that while lenses like the 24-105 might resolve fully on the 5D in some situation, it may not resolve fully on the 5DmkII. In this case, THE 5DmkII FILE WILL STILL BE SHARPER. For instance, the lens might limit sharpness so that the 5DmkII is resolving the equivalent of 16 megapixels. IN THIS CASE, WHILE THE 5D 100% CROPS WILL LOOK SHARPER THAN THE 5DmkII 100% CROPS, A 5DmkII PRINT WILL LOOK SHARPER THAN THE 5D PRINT. The 5DmkII crop looked less sharp only because it was more magnified.
There is no situation in which lens aberrations or diffraction or camera shake will make a worse photo on 21 megapixels than on 12 megapixels. These factors can only reduce the 21 megapixel file down to the 12 megapixel file's level, not below.
Experiment with your lenses, learn the limitations, choose apertures more carefully, and shoot more carefully, and many lenses can fill at least the great majority of the pixels with good detail. Avoid zooms and lenses with a less than stellar reputation for sharpness.
21 megapixels may be nearly double the number of pixels you are used to, but it is nowhere near the 52 megapixels that would double the 5D's resolution. The extra detail and sharpness that 21 megapixels bring are useful, but subtle, and incremental.
Above all remember that it is not a tragedy if you fail to use all of the 21 megapixels, just because they are there. Robert Capa's famous pictures of D-Day could have been taken on a 2 megapixel camera, judging by the detail. 21 megapixels is a facility, not a religion. Use them all when and if you need to.
Edited on Sep 22, 2008 at 09:11 AM · View previous versions
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| Sep 19, 2008 at 03:54 AM |
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