Photographer and author Andrew S. Gibson has released a new ebook, Understanding Exposure, that does a good job of breaking down this fundamental photography concept. I’ve previously reviewed Gibson’s Beyond Thirds and Square books, and like his previous offerings this one didn’t disappoint. Unlike many photo ebooks, this isn’t purely for newbies. Even as someone who’s been involved with photography for over ten years (and having done it professionally for four years), I learned some new things that should improve my images.
Subtitled “Perfect exposure on your EOS camera”, there are portions of the ebook which are a bit Canon-specific, but most of the material applies to digital photography in general and will be of value to a Nikon shooter like me (or Sony, Pentax, Olympus, and so on). Understanding Exposure is divided into three general sections.
The first section of the book covers the concepts of exposure. Beginning with the exposure triangle of shutter speed, aperture, and ISO, Gibson dives into the building blocks of photographic exposure. After explaining the relationship between these three elements, the remainder of the first section explains some of the common ways by which exposure is referred, adjusted, and measured.
The notion of exposure “stops” is explored in depth, including charts that help a reader understand the mathematics behind stops and exposure values. The final part of section one is a multi-page guide to histograms. I’ve seen many explanations of histograms in the past, but Gibson dives into more detail on both the luminance and color histograms than any other resource I’ve seen (9 pages are devoted to the topic).
The second portion of the book is devoted to camera settings and controls that affect exposure. This is where things get EOS-specific, but astute readers can find similar controls on cameras from other manufacturers. This section moves in a logical order, starting with the basic metering modes (P, Av, Tv, M) and then moving into exposure compensation. After discussing the camera settings and the “easy” scenarios, there’s a discussion of how manual lenses affect exposure calculations and a quick look at how (and when) one might want to use an external light meter.
Three Exposure Scenarios
The last part of the book consists of detailed breakdowns of the three exposure scenarios:
- a scene in which the brightness range matches the dynamic range of the camera
- a scene in which the brightness range is noticably less than the dynamic range of the camera
- a scene in which the brightness range is greater than the dynamic range fo the camera
For each of these scenes, an explanation is provided with the photographer’s options for making the exposure. There is a discussion of ramifications of various decisions and a representative histogram is shown.
Summary / Recommendation
Overall this is a great book, I’d recommend it for anyone who creates images although non-Canon users will need to do a bit of translation in the portions which explain camera controls. Whether you’re a photo newbie with your first camera or a veteran shooter, the material in Understanding Exposure contains items of relevance to you. The book is over 75 pages and is provided as a PDF so it can be read on a computer or mobile device. The list price is £7, but if you order by the end of April use the discount code exposure2 to save £2.