A point of view to keep in mind is that people copy deeds all the time.  A person with a photographic memory who looks at a deed and then copies it onto a canvas at home or a laptop with a draw program is no more in violation of the law for copying an image than the person who uses a camera because he or she lacks a photographic memory.  In fact, I would certainly fall on the side of your right to use a camera as a memory aid since you, like most people, probably lack a photographic memory.  Would they stop you from using a sheet of paper and pencil to draw a copy of the deed or abstract data while you sit there?  I doubt it and those are similar tools to aid memory.   Perhaps discreet use of a cell phone camera or video goggles would be less likely to rankle the sensibilities of public servants in your jurisdictions.  Look into the laws governing such matters and proceed with forethough and foresight.