Hi Jason, on the S10 the different aspect ratios which affect image dimensions apply to both photo and videos. If you go into the "camera settings" you will only see options for various video sizes... however, when you are in the "camera screen" (where you take photos) you can change the aspect ratio at the top of the screen and that affects photos. I just looked on my S8+ and that offers different resolutions in the camera Settings for video and photos separately. I think the older Samsung phones had even more options, but I could be wrong.
The file sizes are small as Samsung seems to be compressing the files with a really good algorithym which retains a lot of detail and reduces file sizes significantly at the same time. If you shoot at a higher ISO you will see the file size increase slightly, but still a small file size overall.
I hope you are enjoying using your phone's camera. I only really use mine for grabbing a quick shot to show someone something, as I prefer using my DSLRs and mirrorless cameras for anything serious. The cameras in these phones are fantastic for sharing stuff, that's for sure.
If it is about the size of the saved file there is a "Save options and a toggle for HEIF (High Efficiency image) that will save space when taking a pic, check out the cautionary info too.
Using Galaxy Note 10 +.
So yeah, I'm pretty upset they only give us those aspect ratios and that is the most ridiculous thing ever, they are supposed to be making things better and more user friendly not harder and more "smart". MANUAL WORK-AROUND: So basically you select your aspect ratio then to adjust your resolution the only manual way i can figure is that after you take the photo then cropping/resizing your photo is where you choose the ppi resolution. I don't get at all why I can choose video rez but not picture rez. There are plenty of situations where you need to take a small 600x600 photo and it would be great to be able to just select it then shoot but nope they want you to take the full shot then choose which part of the photo you want to be 600x600. And the reason I know this when you go to crop the photo they give you the dpi and size of your photo and after you're done cropping to your 600x600 photo check the file size its waaaayyyy smaller than the original. Honestly it seems super lazy on the programmers part. I hope this manual work around works for you all but again in no way at all is a better or a "smarter" way of handling our photo taking experience. Edit: after the shot is taken go into the crop area and hit the 3 dots in top right corner there are options in there to resize image. So that would be the quickest fix to this issue. It retains the original image but reduces the image ppi so it fits into whatever size you're looking to get.