How much editing is okay? I've been asking myself this question a lot.
I think it's fine to edit a photograph that is strong on its own and does not NEED to be edited. If you're cropping a image to improve the image composition, if you change the contrast and brighten or darken the image that's totally fine in my opinion. I also often improve the color balance or even change the tones if It think it fits.
If you find yourself editing your images in order to correct them, and not enhance them maybe you should go back and try to take the photo again.
It is amazing how much you can do with Photoshop, Lightroom and co. Just take a look at this...http://www.animal-pics.de/thread.php?threadid=19402&threadview=0&hilight=&hilightuser=0&page=8
Some of my photos are almost not edited at all. Here I only changed the contrast a tiny tiny bit.

Some pictures need more editing. Here I cropped the picture, retouched the water drops on the blanket, changed the saturation and sharpened it a bit.
And I have no idea what happened to this blue streak in the die. First I thought I accidentally did something in Gimp but it looks like that in the original as well?? Weird.

Sometimes I make them black and white.

Sometimes you can tell my pictures are edited. Sometimes you can't. This is a really honest post and here I'll show you some before/after pics. Sorry to disappoint you, not all of my photos are out of cam... I will only post examples where I actually edited more than changing contrast. The last one is edited quite a bit and I want you to know that sometimes I like to create totally new pictures. If that makes sense.



