In This Chapter
Describing raw format Comparing raw to JPEG and TIFF
Balancing the advantages of doing raw against the convenience of JPEG Checking out the DNG format uckily for shutterbugs, the technology of digital photography is always evolving. Earlier compact digital cameras were pretty advanced; their 3-to-5-megapixel capability produced pretty good JPEG images. But these cameras have now evolved to 7-to-9-megapixel sensors, bigger lenses (with vibration reduction), and greater ease of use. You can even shoot in automatic mode or set aperture priority or shutter priority to whet your creative shooting tastes. As a bonus, the macro capabilities of these cameras are phenomenal!
These advances mean you have more choices in equipment and capabilities. Today's affordable digital SLRs (and advanced compact "prosumer" cameras) boast capabilities we only dreamed of a few years ago — but their biggest advantage is that the latest models can shoot in raw format.
Raw format provides the photographer with more options for bringing out the best in digital images. You get more control over color, exposure, and sharpness — and if you're like me, the more control the better. If you give a painter a greater selection of better paints, more brushes, and a bigger canvas to work with, you'll notice the difference in the paintings. Raw gives the photographer exactly that — a wider range of creative choices, more detailed control over color and tones, and a bigger canvas to work with.
Quite simply, a raw file can be described in the same terms as a film negative that hasn't been processed yet — only without the chemical stink. The image data is there, but it needs to be developed. In effect, Camera Raw is the virtual equivalent of the film-development chemicals that were the only way to develop color images before digital cameras. You could say that shooting in raw is environmentally friendly, too! No toxic gunk to bite your fingers or pollute the environment — just you, your computer, and Photoshop CS2.
When you shoot a raw image, your digital camera collects data. The raw image file is just a recording of what the image sensor has collected. In raw mode, your digital camera doesn't do anything with the data, it just saves it to a file. No processing is performed like when you shoot in TIFF or JPEG format. The file doesn't become an image until the photographer processes it. Figure 2-1 shows just what a raw file looks like without being processed. It's dull, lifeless, and without vibrant color.
Because I brought up the topic of film, there is a huge difference between the chemical processing of film and the digital processing of raw-format files. With film, you get only one chance at processing the file. If the temperature of the chemicals are wrong, or the length of time in processing is wrong, the negatives get ruined. You can't go back and do anything to fix that. You only get one shot at developing film. If you make a mistake, your film — and the photos you shot on it — are (technically speaking) hosed . . . wasted . . . toast . . . destroyed. With digital raw files, you can process your images many times! Go ahead and make some mistakes, it doesn't matter! You can always go back to the original digital raw image and process the image again.
Being an old film guy who's developed many rolls of film in my old chemical darkroom, I think raw is a beautiful thing.
One of the reasons the raw photos first appear dull and lifeless is because raw files are for the most part captured in grayscale. Don't get me wrong — there is color information in a raw file, you can see some in the photo in Figure 2-1, which shows how the image looks when first opened in Camera Raw. Color characteristics are recorded for each pixel as red, green, or blue; a raw-converter program such as Camera Raw will interpret the color during conversion. That's why more color becomes visible as you make adjustments in Camera Raw.
Camera Raw converts a raw file by interpolating color information: The raw converter knows the color associated with a particular pixel, but "borrows" color from neighboring pixels to create the needed color. Additionally, Camera Raw opens a raw image with some automatic tonal adjustments made for you, however, saturation is not automatically added. Figure 2-2 shows the same image as in Figure 2-1, after color is extracted in Camera Raw.
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Compared to film cameras, digital cameras are easy to use, fun and extremely versatile. Every day there’s more features being designed. Whether you have the cheapest model or a high end model, digital cameras can do an endless number of things. Let’s look at how to get the most out of your digital camera.