Disable auto enhance in Photos app

same issue here. Super annoying!

What file types is everyone having a problem with? for me, it's NEF files. I spent an hour and a half on the phone just now with Microsoft.... he's telling me its due to the file format, as it doesn't happen with a JPEG... his solution is to stop using that file format... Not sure why there was an option to disable this before, but it's since been removed from the programming.

For me it's with RAW format,he is right about JPG format it doesn't modify the image after a couple of seconds.

Still really annoying since i use it as a quick look to pre sort the one that aren't good enough on sharpness or lighting.

It might be the file format. Here's my perspective for the PNG case. I was looking through a couple hundred PNG files (mostly gaming screenshots for a comp sci university project) and it's been severely auto-correcting the brightness on about 15% of them when viewed in Photos. I used a timer-delayed screenshot to try to capture the 'corrected' vs uncorrected display. Here's a picture of one PNG file the moment you open it in Photos:

And below is the same picture open in the same Windows Photos app after a few seconds, by which time Photos has 'corrected' the image (note that NO settings were changed or edits made, I just let a couple seconds pass; the clock shows 2 minutes earlier because it took me quite a few tries to be quick enough to get a screenshot of the unaltered version) 

It doesn't appear to be destructive (for reference, I set the same picture as my background, and you can see that it's the unbrightened/uncorrected version), it's just how Photos is choosing to display the picture, but I agree it's really, really annoying. And in all ~350 pictures I was sorting through this morning, none of them looked better after this correction.

Please come up with a way to turn this off!

1. It's sort of deceptive, not only because the preview/icon in the File Explorer doesn't match the image Photos displays, but also because Photos isn't saving the picture like that. What if I saw these images in Photos auto-corrected, thought that the photo turned out great, and just went on with my life thinking that the displayed image is representative of the actual file? Because as far as I can tell, if you actually want the saved file to look like the thing Photos automatically displays, you have to go in and edit the brightness/focus/color yourself and then save a copy of it with those changes.
2. Most photos these days probably come from smartphone cameras, and almost all smartphone cameras already have corrections for brightness/focus/colors, and editing apps to change those. So this seems kind of unnecessary as well.
3. It's not really feasible to ask people to convert every image they have to a lossy file format just to view it with their OS-standard photo viewer.

Because I have to go through hundreds of photos, I'm not going to make JPG copies of all of them, look at them using Photos, then find the corresponding PNG of each and sort that as necessary, then remove the JPG as well. I'll just have to download a 3rd party photo viewing application until Microsoft figures out that users do not want their files altered-but-not-really-altered-just-displayed-incorrectly without any user-end notification or consent, and without any functionality to turn that off.