In case this has you worried, all digital cameras have a default setting that automatically sets the white point. This generally works well outdoors. There’s also specific settings for florescent lighting and incandescent lighting. Some cameras are better than others, and when shooting indoors you can use the flash, but under artificial light the only way to be certain is to use a gray card.
Another consideration is the file format. Some cameras only offer one format and that is JPEG. This is a compressed file, and in processing the compression there’s always some level of artifact and loss of information. Generally this is not a problem, but naturally as compression is increased, so are the artifacts. There are software programs that can remove most of the artifacts, but none can add in the lost detail.
That’s one reason why professionals and serious amateurs often select a raw or TIFF format instead of JPEG. The raw format stores the actual information collected by the sensor and allows the photographer to manipulate that data. TIFFs are uncompressed images with the camera settings applied, but not many cameras offer this format.
Raw files are approximately the same number of pixels as the sensor. Because the raw data is interpolated to provide red, green, and blue pixels, the file size of a TIFF will be at least three times the size of a raw file. If your camera records in more than 8 bits per color channel, typically 10 or 12 bits per channel, the TIFF file will be six times the size of the raw file.
To add some clarity to this, I’ll use my Canon 10D as an example. The raw file is 5.8 megabytes. At 8 bits per color channel the TIFF file is 18 megabytes. At 16 bits per channel the TIFF file is 36 megabytes.
The camera only records 10 bits per color channel, but the image can only be saved as either an 8-bit or 16-bit file. That’s just the convention and there’s no getting around it.
So what’s the difference? Eight bit color is sometimes described as “true” color. It’s about what we can see, or readily discriminate, basically 256 levels of intensity in all three channels — red, green, and blue. That also corresponds to the binary system that our computers use and display. In binary it takes 8 bits to count to 256.
However, in the real world there’s an infinite number of colors. And professional grade photo printers are capable of printing a wider range of color than our monitors normally display. So, relatively speaking, a camera that records 10 or 12 bits per channel provides more color information, and therefore detail, for those who are capable of printing the wider gamut or range of colors.
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