I am going to start a short series on light here in the blog, which will be emulated in the online book of photography—in a more linear fashion, both here on the Two Geeks and a Girl Website.

The ways in which we handle light to create an image depend ultimately on the way it is captured by the camera.  Digital photography has revolutionized this because of the way in which the sensor works and because of the unbroken stream of information as the image data moves from sensor to memory card and onto the computer.  Camera sensors react to and record light in a fundamentally different manner from analog film, and this is the basis for special control that digital gives over the image.  Digital photography gives almost total control over the capture and manipulation of light.  Not just more so than film, but in a different league altogether.  This makes a comprehensive guide to all the techniques and possibilities a necessity, not just to help digital photographers through the minefield of white balance, clipping highlights, and dynamic range, but so that they can get the most out of any situation, tuning the effects of lighting for high-performance photography that realizes their creative needs.

The camera is no longer simply a vehicle for carrying a light-sensitive receptor, as it arguably was with film.    The sensor is not simply a component that fits behind the shutter and lens that can be slotted in and out.  Rather, it is a key part of a system designed to interpret and process its response.  An increasingly important part of this processing is automation of one kind or another.  With the huge capacity for processing the image within the camera, there are inevitably ways of automating everything, and that includes the key light settings.  These are, of course, exposure, white balance, and contrast, and the convenience of the auto option applied to any of them is that the image can be assessed objectively and rendered “correctly.” Auto is the natural default for image processing, for the simple reasons that brightness, overall color and contrast can be measured, and then adjusted to fit known values.  The “correct” light settings are an exposure and contrast that puts the mid-tones near the middle of the histogram (more on that later) and avoids loss of highlights and shadows as much as possible.  It also needs a color balance that takes the mid-tones that are close to neutral and makes them exactly neutral.  All of this is a huge convenience, but only as long as we know what the camera is doing on our behalf and that we can over ride it if and when we choose to do so.

Check back soon, as I will be covering some of the more important aspects light plays in your photographic adventures.

Richard Seymour

www.jargra.com