Digital scan back

Digital imaging devices typically use a matrix of light-sensitive photosensors, such as CCD or CMOS technologies.

[1] The main advantages of this technology are the extremely high image quality and the huge resulting files.

This translates to very accurate color reproduction, because every pixel is measured individually, allowing printing in very large sizes without loss of detail.

Previously only large format film cameras could print to similar sizes.

Scan backs also have the advantage of not being subject to light fall-off due to off-axis lens positions, so wide angle lenses and perspective shifts on the camera can be used without issue.

A somewhat less obvious advantage lies in that scanning backs are typically created using trilinear CCDs.

This means that for every pixel position a separate measurement is taken for red then green then blue.

(With the notable exception of Foveon) The downside of capturing images this way is the amount of time it takes.

That means we can evenly divide the x axis in 10,000 points, so the array has to take 10,000 exposures.

The newest sensors can achieve even bigger file sizes, up to several gigabytes.

The first commercial digital scan back was introduced by Leaf (now Phase One) in 1991.