Do photocopiers deteriorate photos and documents worse than scanners?

Question

I think that both deteriorate the originals, but is photocopying worse than scanning? Both use lights (and flashes on cameras are said to be bad) in the process. Can anyone explain the difference between the duplication processes? It seems like this is something that I should be able to find on the internet, but I can't seem to be able to find the right search words.

Answer 1

Modern photocopiers are actually digital scanners with printers, so there is no difference there. But different photocopiers use different types of light so that's where you'll find the difference.

However, the photocopier will give you a paper copy, which if you want to copy, you will have to scan/copy again. A digital scan can be copied forever with no loss. Hence, you should scan the document, not copy it.

Also, the biggest risk to your documents will rather come from the physical handling. This is why digitizing of old documents rather is done with overhead high resolution cameras that in scanners, because it means you don't have to move the document upside down or press them flat, which is especially important with books.

That technique does need a lot of light, which is why you need to care about the lamps, and as per Fortiters answer, use UV-filtered fluorescent lamps.

But if your documents are not books, but flat separate pieces of paper that are not extremely fragile, scanning them in a scanner should typically not make any significant damage.

Answer 2

Googling {scanner lamp color temperature} led me to Care and Handling of Physical Collections for Digital Conversion at Yale University Library, which includes the following advice:

Two considerations need to be made when considering light levels for digital conversion: heat gain and exposure to radiating energy. Proper color temperature (around 3500 degrees Kelvin) is needed in order to achieve a true-color scan, but halogen lamps produce too much heat, causing problems for collection items, such as rapid dimensional changes and desiccation. The recommended alterative is high frequency, low wattage fluorescent lamps, which give the correct color temperature with little radiant heat.

These lamps need at least 15 minutes to reach their maximum intensity. These lamps should be fitted with UV-filtering sleeves to eliminate the ultraviolet component; UV is not necessary for the eye to perceive color and does not affect color temperature. Because total light damage is accessed through the intensity of the light source and the length of exposure to the light source, it is important to limit both as much as possible. Precautions – such as covering the item when it is not being scanned – should be taken whenever possible to reduce exposure time.

Some of the links to references in the paper are broken but it may be worth seeking those papers in alternative repositories.