Digital cameras can cost from under $50 to over $37,000 or even more. If you are considering a general purpose camera, for family gatherings, vacations and such, you may also wish to consider whether or not the same camera might also be used to gather documents, take notes in libraries and to copy microfilm images.
In determining the utility of various digital cameras for copying documents, I have been comparing the camera images with those obtained from a flat bed scanner for the past few years. The reason for the comparison, is to determine whether the digital camera could replace my scanner as a primary method of entering documents into digital files. Or do I still need both a flat bed scanner and a camera? Cost is no longer a real factor, the best flat bed scanners cost lest than $200. See Canon ConoScan 8800F. Also, high quality (more than 10 megapixel) cameras are now also less than $200.
There are quite a few reasons for considering a digital camera. Obviously, it is a lot more convenient to carry a camera around rather than a flat bed scanner. It is also impossible to take pictures (i.e. grave markers and other subjects) with a scanner.
In determining the difference in quality, I have periodically taken three document types, a letter, a certificate and a photograph, as the the basis for the comparison. During the past few years, in addition to the cameras I have owned, I have borrowed higher resolution (more megapixels) cameras to test whether or not I could accept the quality of the photographs from the digital cameras. I would scan the documents and then take photos with with camera. I would then compare the digital files, magnifying the images on the computer screen to show the details.
Digital cameras did not begin to have nearly the same quality as scanners until the digital cameras exceeded 6 megapixels. At 10 megapixels, in my opinion, a digital camera gives essentially the same quality of resolution of a printed document, except a photograph, as one scanned on a flat bed scanner. However, photographs are a different issue. A digital photograph of a film photograph, even at 10+ megapixels does not compare favorably with a flat bed scan of the same photo.
So, if you are primarily using your scanner for photos, for the time being, you may still need to keep it. But, if you are making photocopies of printed documents or scanning them into the computer with a scanner, using a digital camera with over 10 megapixel resolution, is a much quicker and more convenient alternative. For example, my Canon single lens reflex camera came with software allowing me to control the camera using a USB cable, and take pictures, from the computer.
Afterthought, even if using a digital camera is more convenient and saves copy costs at the repositories, you must make sure the library or repository allows you to take pictures of the books and microfilms.