Image quality
In daylight, we're seeing predictably great photos from the main camera - detailed and clean, with Samsung's signature, highly-competent noise suppression leaving pretty much no trace of noise while preserving detail. Colors are lively but not over the top and dynamic range is excellent - as our snail test shows.
The telephoto camera is also a proven player, and we've come to expect solid results from it in bright light. In such conditions it captures images with very similar quality to ones from the main cam. Comparing to the S9+, we're inclined to think we're seeing a slight improvement in contrast.
The ultra wide lens predictably has some barrel distortion as all lenses this extreme. There's a setting for correcting the distortion in software, and it helps a bunch. Here are a couple of sample images from our S10+ review (we only discovered the setting after returning the S10 review unit, and the S10+ was still around).
Distortion aside, at fit to screen magnifications the images look pretty nice with pleasing colors and very good dynamic range as far as these types of cameras go - due to the extreme coverage you're inevitably going to get a wider margin between the lightest and the darkest area in the frame, and the HDR algorithms can only do so much.
Pixel-level detail is also respectable if you don't stare too closely at the corners and if you get the focus distance right - that's not the case with the second sample below where the closest flower pot is too close to be in focus. So that's one of the main uses cases for an ultra wide camera that the Galaxy S10+ can't excel at due to lack of AF. But we feel like we may be judging it too harshly.
In low light, the main camera captures excellent images with well defined detail and little noise. Dynamic range is also very good - check out the flood lights on the top floor of the yellow building below, usually clipped to white.