These days I assume that it is fine to take photographs in museums, galleries, archives and libraries unless I see a sign saying I can't. If I see a sign saying I can't take pictures I wonder why I can't photograph. As long as flash options are turned off photography is safe for the items. As long as people are considerate, photography is not disruptive to others - and it should not be disruptive to others. I am not a fan of selfie sticks, but other than the use of these, mostly people are considerate when photographing in galleries.
In the Metropolitan Museum of Art they allowed photography, except of four paintings by Van Gogh. It was a special exhibition, but not their only special exhibition. There were lots of people looking at these four flower paintings, but there were lots of people throughout the museum. I was wondering if it was to do with merchandising, but many of their items have copies for sale. I do not know the reason, nor was asking possible. It did not interfere with my enjoyment of these paintings, but it made me think about why photography seemed okay elsewhere in the museum.
If you stop people taking photographs, it can be helpful to explain why. This can be part of the educative process.
Photographing collection items, or spaces is different to photographing people using those spaces.
Cambridge Public Library, MA required any photography to be have paperwork filled in, carried, and shown to all staff who asked. When I visited their central library I was aware of this requirement. I was impressed that every staff member who saw me with my camera (and I was trying to be unobtrusive), asked to see the paper work (or commented on the need for it until I showed it to them). The consistency was impressive. I do not photograph people in libraries (except for occasional back or partial views). Sometimes it means that parts of libraries can not be photographed - so be it. I don't want to be disruptive to someone's use of the space - not have to engage in a long discussion about permission.
If you ban photographs in certain areas, it can be helpful to educate your community as to why they are not permitted.
