Most coins look
fine, but if there is ever a problem for me it is that they are too dark. But, generally just right. I use laptop or desktop only, never a phone or tablet. You could get your screen calibrated and there are some
tools online that can get you close without needing to buy a calibration tool or taking it somewhere for that. These are known color and white/black blocks of color images you can then adjust your monitor settings for to get best look. That lets you know you are producing
good pictures on your end, although you can never control how other people have their monitors set. My real issue is with the photos of Lots, a pile of coins is really difficult to tell much from, especially when only one
side is shown or there is overlapping. With lots, the zoom is not very helpful as it is with individual coins.
Virgil