Will the book make me a better photographer. After Christmas I am completely broke. I understand that focus is one of the basics for a good picture and I have had focus issues in the past, will the book help me? I can come up with the nominal sum but want to spend my money wisely. I have the book "Mastering the 7100". Paul
Well, it will make you a more knowledgeable photographer.
He explains pretty much every aspect of the Nikon focusing system. He explains how to use the different modes, focus points, back button focus, etc. He is a wildlife photographer so, if you are having any difficulty shooting things that move around, you will get something out of this book. It is over 400 pages of good information. Not every page will pertain to the D7100 because he gets specific for different camera models, but maybe the information will be of use to you in the future if you decide to upgrade your camera.
He is a natural teacher. The text is easy to read, and he is funny. Great images with samples for you to look at are in there.
I think if you practice what he shows, I don't see how you couldn't improve. He explains how he uses the focus system with real life examples. He also shows what can go wrong and why and what you can fudge and still get a shot.
Watch his reviews and tutorials, and you will see what I mean. I learn something even when I watch his reviews.
https://backcountrygallery.com/understanding-nikon-af-modes/