Snapping photographs that will later be used for textures in 3D, is never a bad idea. Eventually you can have a personal library of material that can be used in 3D work, and more. One of the issues with taking a photo when inspiration hits, is that it can be difficult to grab a photo under ideal lighting conditions. Having an image that is unbalanced will limit its usefulness overall. Being able to equalize, or even out the tone in your images becomes important of you want to use them as repeating textures — But how?
There are a few ways to even out the lighting on your shots. One popular technique is to use a High Pass filter in your favorite image editor. Jørgen Håland provides a nice explanation of the process. Shifting the colorspace over to LAB, and then applying a High Pass filter, can make short work of evening out the tones in your textures.
Haland has been covering creating your own ID maps from image textures as prep work for 3D renders.
If you’ve never used LAB before, it’s important to note that the LAB colorspace is a unique one. It was developed to be a device-independent color space, yet its most compelling feature is the fact that it extracts the luminance on its own channel (the “L” Channel). This makes it a great color workspace for focusing on anything that deals with an image luminance values.