A Photographer’s Guide to Focus and Autofocus: From Snapshots to Great Shots
Author: Alan Hess
Alan Hess takes on the daunting task of explaining the auto-focus systems of cameras and what settings to use. There are so many brands, so many models, and so many options that this could get very confusing, but he does a good job of explaining the choices and when to use them. To do this he concentrated on Nikon, Cannon, and Sony but in a way that can be generalized to other manufactures as well.
He starts by defining terms as used by these three systems so that we are all on the same page. There is an understandable description of how auto-focus works in general for through the lens shooting and for live view. Alan includes other important factors like controls on the lens and how exposure settings affect focus.
With this under our belts, he gives us a look at the sometimes perplexing decisions photographers have to make about how many focus points to use and what focus mode we should be in. In these chapters, he explains the differences between single point AF mode, dynamic mode, automatic mode, and group mode. He also discusses how multiple focus points work together when they are chosen rather than a single point option.
More practically, after explaining how everything works he gives us examples of when we might want to use the various modes. He also includes a chapter that addresses common autofocus problems and how to trouble shoot them. The book concludes with discussions of when to use manual focus, how to get sharp photos and how to focus for videos.
All in all, there is a lot of material here. It is probably best read with your camera manual in one hand and it in the other. It will define all the confusing terms that are in the manual. You can concentrate on the information on your brand of camera and on the features that your camera manual shows your camera has.