High Dynamic Range Imaging - Scanning Film

Scanning Film

In contrast to digital photographs, color negatives and slides consist of multiple film layers that respond to light differently. As a consequence, transparent originals (especially positive slides) feature a very high dynamic range.

Dynamic ranges of photographic material
Material Dynamic range (F stops) Object contrast
photograph print 5 1:32
color negative 8 1:256
positive slide 12 1:4096

When digitizing photographic material with an image scanner, the scanner must be able to capture the whole dynamic range of the original, or details are lost. The manufacturer's declarations concerning the dynamic range of flatbed and film scanners are often slightly inaccurate and exaggerated.

Despite color negative having less dynamic range than slide, it actually captures considerably more dynamic range of the scene than does slide film. This dynamic range is simply compressed considerably.

Read more about this topic:  High Dynamic Range Imaging

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