Juan Carlos
Size of material does not matter. Some Photoreaders PR newspapers ... I for one do not as too much negative energy in news papers!
If you're beginning, use the center of the text book to find the blip. You could alternatively use the four corners of the book to imagine a X from corner to corner.
As a test try this, if you're at your computer reading this, relax, and casually glance down at your keyboard. Notice the items to your left and right. Your peripheral vision covers a great amount of area doesn't it? So to will it when it comes to PR'ing.
This whole systems take time to develop, play with it and let it develop naturally.
I've been at it for months and I'm just starting to get comfortable with it ... so, go easy and look for signs where you are improving.
