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Looking for help on quality of shots
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I took some more shots over the weekend on my 7-200Lf4 and they are a bit sharper at 100%. I’ll process them and stick them up for comment too.
I don’t know anything about Canon-
If you need to test a lens, you need to eliminate everything that will degrade its performance, that’s not related to the optics-
there looks like there’s movement in the bee shot, for example-Ideally, you’d shoot from a good tripod, with the mirror up-
you can download the USAF Target, print it off, photograph it (properly)
and determine the resolution by counting line pairs-
though this is a test of the system, lens and sensor.There are other targets, sine patterns, which might be more suited to digital sensors-
All digital images need sharpening, and as these haven’t been sharpened at all, I’d say they’re not bad-
The performance of all sensors degrade as soon as a lens is used to create an image-
resolution can never be as much as the number of pixels produced by your camera,
and most lenses usually perform best at one or two aperture settings-
degrading slightly when used wide open and stopped down, though there are some exceptions-These tests you’re doing are highly subjective,
but they do illustrate the performance of the system with the type of picture you want to take,
so they’re useful to you-However, different things need to be addressed;
testing for focus accuracy might be different from testing for resolution-
and resolution differs from sharpness anyway, since sharpness is subjective, and resolution can be empirically measured-As I mentioned earlier, comparative testing using a good known prime for reference might tell you a lot-
joseph
Thanks Joseph. I’m going to do a cross reference check of four lens shooting the same scene, tripod mounted, before drawing a conclusion.
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