This is effectively a textbook for Renaissance artists. It is split into three sections, the first dealing predominantly with issues of composition and perspective, the second with light and shade, colour and the artist's duty to his art and his public, and the third predominantly with what qualities one must bring to the job of being an artist.
If you are only loosely interested in art as a pragmatic practice, and you don't have some mathematical knowledge which will steer you through the first section it may be rather impenetrable in places. I am one of these people and found myself really struggling with the first section.
It is however fascinating as a glimpse into the mindset of a humanist scholar and as someone practicing on the cusp of what will become the Renaissance. I picked this up because I am studying Leonardo Da Vinci and this book was massively influential on him. This is what is most fascinating to me, that the things which Leonardo did and propounded, and which many people judge him as a genius for, were already laid out in essence in this book, written many years before.
This is a short book, coming in at 96 pages, with thirty odd of those taken up by the introduction. The introduction however is very valuable and to me the most illuminating part of the book, one which certainly gave me enough impetus to keep going with the actual text itself. The introduction is written by Martin Kemp, a world renowned expert on Leonardo Da Vinci. His writing is fluent, interesting and illuminating.