Scott and i have been getting super nerdy about reviews and image quality. It turns out that figuring out resolution of a camera is incredibly difficult and depends quite a bit on sharpening. If you use JPEG, then there are lots of settings and all cameras need some sort of sharpening. If you use RAW, then it depends on how much sharpening is used in post processing.
Finally, the resolution changes depending on whether you are looking at the center or the whereever on a lense, the aperture (the sweet spot is usually F/4-F/5.6) and the focal length on zooms (middle usually being the best). Net, net, most reviews are not comparable, so it is good to see folks using Imatest, but again there are zillion parameters. Here are some of the sites I use with caveats:
- Lensrentals.com. Their blog is good and they test since they have a large fleet of lenses. They use unsharpened RAW so most of the time, their resolutions will be low. All cameras can use some sharpening, so they are a lower bound.
- Photozone.de. Klaus is a one man shop and he also tests using Imatest. it isn’t clear what parameters he is using when he shows his figures
- PCMag.com. They use out of the camera JPEG which mostly is pretty useless. Sadly, no one seems to try to optimize the lens/camera/sharpening combination, so none of these tell you the best settings that work for a camera.
Then we have DXOmark. They use their own proprietary test and it is pretty much impossible to tell what they are doing but at least they are trying. DPReview.com also uses their figures now, but it is too soon too tell.
And then there is imaging-resource.com and its sister slrgear.com that uses photos taken and some sort of blur guide that I’m not sure how to read.
Finally resolution is just one of the many parameters, there are others that are measurable like distortion, chromatic aberration and vignetting, but sadly none of these tests measure the effect of tweaking the parameters of the camera *and* the post processing software. What we need is a test that is truly end to end, that tells you how to set the camera, what to set the lense and how to set the ACR parameters to get the most from a camera.
