Camera Sensors At Work: how your digital camera turns light into an image

Photography Cheat Sheet: how your digital camera turns light into an image

JPEGs and Raw files

Technique assessment from our professional photographer: shoot in raw format

With JPEG pictures, each photosite can register 8 bits of data, which equates to 256 different shades of brightness.

This might not sound like much, but when it’s combined with the full colour information generated by demosaicing, this generates an amazing 16.7 million possible colours.

Raw images offer even more colour detail. Raw files store 12 bits of data, equivalent to 4,096 separate shades rather than JPEG’s 256.

Advanced camera models can also save 14-bit raw files, equivalent to 16,384 brightness levels that can be recorded for each pixel.

Regular JPEG images will still show a full range of colour and tones, but raw files have the potential for a wider brightness range and smoother tonal gradations.

Whether you choose to record in JPEG or raw format also affects the way a picture is processed, and any in-camera settings for saturation, contrast and sharpness (such as Nikon’s Picture Controls or Canon’s Picture Styles) you use are a case in point.

Changing these settings is a bit like changing the type of film in the old days. Each one gives a different colour balance, saturation and contrast. Vivid gives you rich, vibrant colours, while Monochrome shoots pictures in black and white.

If you shoot in raw, a Nikon Picture Control, for instance, isn’t applied to the raw data, but simply stored alongside it, so you can ignore it completely.

PAGE 1: How your camera turns light into a digital file
PAGE 2: How sensors work
PAGE 3: JPEGs and Raw files


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