Mirrors, Cameras and Photoshop: Tools for Artists

Last week I went to Big Lots and bought a mirror- about a 24x30 size and hung it in my studio- about 8 feet behind my easel.
Normally I walk away from my painting anyway as I paint to view it from a distance. But the reason I needed it was because - I don't have room to get very far away, and in any case, when one views paintings in progress your eye gets used to it as you work: Flaws or errors are more readily seen in the mirror image. Also a mirror allows one to

• View the painting in greater distance (twice the distance from mirror to image) and are looking at less detail. (Helpful in cramped spaces.)
• Judge balance/ symmetry/ spacing of objects in a painting/drawing show up better
• Value patterns. Light and dark masses are more evident

This is very helpful in landscapes, but here is a still life I just started

These are some landscapes I've been working on for an upcoming show...

The other thing that I use is a small camera in studio or my phone camera. 

With a camera I can look at my landscapes and convert them to B&W to judge values or use the clone tool to remove fences and telephone poles, etc before painting: I this one I moved a tree around to see how it would look"

Before

After with changes made with "clone" brush.

Ends up, I actually moved that tree BACK and put a smaller tree in the painting...

Also, I use Coriel photoshop to do some things to manipulate paintings.... like the "barrell distrotion" in this photo. That is causing the appearance of curved edges on the sides of the painting. Below is a correction of that and I also "clarified" it by making the light dark contrast stronger like the actual painting.

I've learned all these camera tricks and photoshop manipulations  on my own, just playing around with the program. I am no expert and am sure others can tell me a helpful trick or two!