I went from using GL_RGBA8 to GL_ALPHA8 with glTexImage3D. My images were grayscale and I wanted to slim down on the amount of data used. I was setting Red, Green, Blue, Alpha to the same value. The RGBA8 image looked fantastic. The ALPHA8 image looks like an overexposed photograph. Any idea what I am doing wrong? Anything to look at that should have been adjusted along with the change from RGBA to ALPHA?