Originally posted by Peter Zack As has been stated, there is evidence that diffraction issues are showing up in higher MP APSc cameras.
Diffraction occurs independently of the sensor resolution. If we had a sensor that outresolved all lenses in existence then we wouldn't need to increase resolution anymore. But we are nowhere near that. If you take your "diffraction issues" argument to its conclusion then you must go back to 2 (two) MP, because any higher resolution will show softening due to diffraction below (i.e., aperture ratios smaller than) f/22.
Originally posted by Peter Zack My K10D is my macro camera and produces a sharper ISO100 image than the K20D can. I can easily see it in prints and on the screen. That may be CCD vs CMOS to a degree as well but I suspect MP has a lot to do with it.
Resolution cannot be the culprit if you compare at the same output size. If you look at 100% crops, of course the higher resolution sensor will look worse. There are a number of factors that could come into play even when you compare at the same output size (which requires downscaling of the higher resolution image which increases contrast and removes noise), e.g., sensor technology, but resolution as such cannot be the culprit.
Originally posted by Peter Zack But that being said, I've printed K20D images up to 60" on the long side.
To print this with 200dpi (300dpi is the professional standard) you would need a 96MP sensor. I realise that such a big print will imply a larger than usual viewing distance and that you don't need 200dpi to make it look good from a distance, but if you are getting close your 76dpi won't look good.
Originally posted by Peter Zack What benefit is higher MP?
To print 60" at more than 76dpi and to be able to crop an image and still print it large. Sometimes you want to crop because you found an image within an image. Sometimes you want to crop to gain reach. If you have a very good lens then cropping to get more reach is much better than degrading image quality by using a teleconverter.
Originally posted by Eigengrau I'm more inclined to listen to someone's opinion about photographic equipment if they have some work to show that they are serious about the art.
Sure, that's a valid position; you are of course free to disregard any opinions by non-photographers. However, one also has to accept that some people are more about the gear than the images and that they are fully entitled to that attitude. Surely the camera manufacturers don't mind the business with them. N.B., this has nothing to do with Ogl. I'm not making a judgement about him being a gearist or not. All I'm saying is he is entitled to his opinion independently of his qualities as a photographer (which may be excellent).