01855 811 799 info@drumscanning.co.uk PDS, Mheall Mhor, Brecklet, Ballachulish, UK. PH49 4JG


Please note that we are on holiday in September and orders made between 7th of September and 7th of October may not be complete until the 19th October.

High Contrast Edges

Because most scanners use a ‘large’ light source, light inevitably bleeds from areas of light into the shadows. This results in glowing around light/dark boundaries, commonly known as halation. Even when this isn’t obvious, it can reduce contrast and hence perceived sharpness.

Drum scanners use a fine fibre optic light source illuminating a single pixel at a time (effectively masking all but the one pixel it is working on). This means that the process of making a high resolution scan can take over an hour at the highest resolution, but it also eliminated nearly all halation.

Here is an example comparison of the results from scanning a very high contrast Fuji Velvia 50 transparency on an Epson V750, an Imacon 848, a Howtek 4500 and a Heidelberg Primescan D8400.

halation