Other helpful guides:
The librarians at the University of Illinois at Urbana-Champaign have created a very nice guide for the Digital Historian Series on using digital cameras in archival research. It presents excellent information on desired camera features, picture taking techniques, file organization strategies, backup practices, computer software, articles, and links to further information.
Digital workflows for the Archives is a 2013 article from ProfHacker that walks you through the workflow of a researcher who chose to use his iphone and a scanner app rather than an SLR camera. While there are now more options in terms of tools, the same workflow could be applied.
A digital camera, whether it is a high-end DSLR, palm-sized point & shoot, or iPhone, can be used as a scanner. And it can save you a lot of time and expense, especially if you do research in rare book collections and archives. This guide covers the issues that camera-wielding researchers might encounter in using cameras as research tools in libraries and archives.
Policies developed for camera use in special collections facilties generally provide safeguards for issues as: