Well I’m not sure about most photos, because sometimes it’s obvious that a photo had been edited (like it’s colours are a bit off, maybe the image is too bright, etc) but half the time I can’t even tell if an image has been edited either :3
Unfortunately I don’t know of any ways of how to directly tell if an image has been photoshopped.
As for my blog I photoshop a lot of the images, but I don’t really make much of a difference to them, most of the time I just remove watermarks/logos and maybe enlarge them a little bit to make them more hq, I try to keep the image as normal as possible, because most people use my images for editing anyway and there’s no point in editing an edit I guess x3
Sorry I wasn’t very helpful ;A;
Download picture Is there a way to know if the photo of idols posted on the net had been photo shopped? I'm not complaining :) I think most idols' photos are beautiful without editing. Btw I'm ignorant in the use of photo and video editing software :) pack .zip photo : link
