Not every photo shoot is going to go the way you want it to or you're never going to be able to duplicate the exact moment, lighting, or subject matter for a reshoot. For whatever reason, many photographers if not all will edit their photos to get what they want or at least close. It could be fixing blemishes, adjusting the exposure, enhancing colors, and so on.
There are some things you can't edit or add to your photos, and you will still need to get the proper angle, catch the emotion of the subject, or create an effective composition in your photo that can't be corrected in Post Production. All this will come from technique and much trial and error. There will be times when you will spend all day taking pictures and only have 1 if not none you like. But with practice, you can make adjustments while you are shooting your photos that will make needed changes later much smaller.
Editing photos is not something new it has been done since the invention of the camera. Just the way you edit is much different. The conversion from actual film to digital also made the editing process a digital process with the use of programs.
In the example of my Silverback Gorilla photo, I got the angle I wanted and his expression is perfect. But I don't like the background or some of the shadows. All these items are taking away from my subject.
Changes Made to the Photo
The program I use and prefer is Adobe Lightroom to edit my photos. But there are many programs out there that will do the same thing.
First off, I wanted to adjust the exposure, and contrast and adjust the blacks and whites to make his features stand out more. I then adjusted the shadows around his eyes and enhanced the colors in his eyes and the fur on his head. All this still didn't make him stand out like I wanted, so I created a mask around the background to make it completely black. Now he stands out. Finally, I cropped the photo moving the Silverback Gorilla to the left more and completing the composition I wanted.
In Conclusion
The most important thing any photographer should learn is that you're the “photographer”. It's your art, your soul, your expression, your photo. Only take advice and knowledge from people, don't take their criticisms and negativity. Like anything you want to perfect, it will take practice and failure to finally get what you want. Good thing digital film is cheap…..