JTW, I see you're using an IPhone 7, and it should be taking
superb images.
Couple suggestions. First, you might clean the lens, as I believe
there is a film on it. Soft cloth, couple drops of ISO alcohol and
a couple drops of water on the cloth, then wipe. Should clean
it up nicely.
Also, try taking pics in natural light when you can. Florescent
lights (CFL's) cause the image to be yellowed.
Yes holes do go all the way through to be mounted