Archibald wrote in post #19411439
I do some crazy crops with the 90D. I don't claim they are all successful. Below is an ant, cropped to 798x568 px, which is a bit less than half a megapixel out of the 32.5. That's about one and a half percent of the sensor. There is probably diffraction present, but with the flare from the flower, noise, and probable focus inaccuracy, it is hard to know what is what. Processed in LR with the usual controls.
That's like a ~13.5x crop from an 83MP FF; a much smaller sensor area than 1/2.3" sensors (~5.56x).
Looks like in the pursuit of visible fine detail, you used a bit of sharpening and/or diffraction deconvolution, which creates that textured noise, but of course, you are sharpening levels of detail that are not captured with much larger pixels, so that has to be kept in mind when people complain about the noise. Personally, when a lot of sharpening is needed, I try to do most of it with edge-only sharpening, so as not to emphasize the dot dither of noise. I would like to see more flexible sharpening tools, like ones that have separate sliders for edges than for dots, each with its own strength and radius.
You used ISO 160, which doesn't show too much noise with no extra sharpening, but sharpening can quickly make the noise more visible, especially in flat areas of trouble colors. I found with the 90D that If you had a scene that did not have highlights to protect and was exposed for ISO 32 at the ISO 100 setting (1.67 stops of ETTR), the RAW files could receive ridiculous sharpening without the noise becoming noticeable.
Anyway, your noise is what I would call "superficial"; it is noticeable, but would quickly disappear out of consciousness with a higher-res display, even at 100%, or with the slightest visual impairment (you forgot your glasses or was the wrong distance from the monitor to focus perfectly, or you squinted), or in a video, where the shallow dither would perceptually disappear with successive frames. Well, the R7 has digital zoom for FHD, so that may make for some very high magnification video, where the noise should be subliminal.