content: This book is very good, but slightly out of date. For example on Kodak's website, the data shown indicates better reciprocity performance on Kodak Gold 100/200 speed film than for 400 speed(or 800 speed), but in this book it has different information. Also some newer Nikon lenses like the 70-300mm 4-5.6 D zoom lenses are not included in the charts. It doesn't contain very much information on data backs or Photo Secretary either, but does contain very complete operating instructions for the cameras that it lists (The F5, F4, N90s/F90X, N70, and FM2). It includes quite a bit of information on techniques and some helpful tips.