Q:

Why are scanning devices (such as FlipPal) allowed in some archives, but not in others?

The American National Archives and Library of Congress both allow the scanning of documents with some scanners (see what's allowed and what's not). FlipPal is one of their approved ones. Lorine McGinnis Schulze has also had great success doing personal scanning at her local archives (Olive Tree Genealogy blog). I've recently purchased a FlipPal and love it for home use, but now I want to start bringing it along on my research trips to repositories and am intimidated by the many organizations that have a blanket rule "No Scanning."
Is there something that the National Archives knows that others don't? Wouldn't they be one of the best judges of whether something is harmful to the records or not? Or, are they just weighing out the benefits vs. risks with letting people use these scanners... Like, increased access to records in exchange for the risk of some damage accruing to the record?

A:

One issue with some scanners and flash photography is the bright light they put out may, over time, damage documents. FlipPal was designed specifically to work with low light, which may account for why it's one of the approved devices. 
As to photography, I expect that as @ColeValleyGirl says, it's partly due to being able to charge copying fees. Another issue, I guess, is that since an archive cannot control camera flash use, they may err on the side of caution by preventing any camera use, even without a flash.

A:

This isn't a direct answer but may be relevant: There's a similar situation in the UK with photographing documents in County Archives. In my experience, some archives allow it for some documents (which documents depend on the conditions imposed by the person or organisation who originally deposited the document at the archives). Others refuse to allow photography, but will make photocopies of some documents for you for a fee. 
So I suspect it's a combination of copyright issues and the need to bring in funds as well as concerns about conservation.
TNA (The National Archives) don't seem to have any problems with photography, but I guess they already know what the copyright situation is with their documents, as they're all "nationally-owned" documents.

