A very nice overview of digital photography for OS X

TidBITS: Reality and Digital Pictures is a very practical approach aimed at people who know photography. Any article that begins by setting gamma is interesting (note that a gamma of 2.2 makes the OS X chrome look dull), especially when it continues with a very modern overview of how we perceive the visual world:

Eye vs. Camera -- To begin with, let's dispel the notion that a camera records what the eye can see. It does not and it cannot because a camera functions nothing like the eye. With a lens of normal focal length, a camera records an image with a diameter of approximately 45 degrees. It records the entire image at once and the image ends up as a print with a range of intensity from black to white of approximately one hundred to one. In contrast, the eye sees an area about 180 degrees across but it sees most of this with acuity that ranges from bad to dreadful. It sees sharply just in the central 1 to 3 degrees. To see a scene clearly, the eye must scan it and the brain must assemble the accumulated information. However, the eye rarely has time to sample more than small portions of a scene with its spot of clear vision so most of what you see has no optical source, it is an inference. Your brain infers information largely by generalizing from what it has encountered before. In doing this the eye and brain have to handle contrasts of light that exceed one million to one.

It's only recently that non-specialists have become aware of how much of our visual world is illusory, and how little data our brain has to work with. Fascinating. Think about what happens when you move into an environment that's unfamiliar, such as going from a city to a jungle. How much can the city dweller truly perceive in the jungle? Imagine transition to a setting even more different? What happens to our visual world as our brain ages and becomes less able to make reasonable interpolations of data ...

Update 12/13/05: I posted the above on scanning the article. On deeper reading "very nice" is an understatement. This is the first article I've read that convinced me I'll eventually move to processing raw images, probably to TIFF or PNG or JPEG 2000. It's the most impressive digital photography article I've ever read.