Camera
The detail rate of the resulting image depends on the number of megapixels. This setting is especially important when printing images on large media. So, experience shows that for high-quality digitization of documents in A4 format, it is necessary about 1-5 MP. Working with A3 documents, you need about 5-8 megapixels. For A2 format, you need 8-15 megapixels. But digitizing documentation in A0 format requires 10-20 megapixels or even more, depending on the required print quality.
Resolution
Resolution determines the depth and detail of a digital image. Resolution is especially important when displaying images on the screen, as well as printing digitized documents.
A4 format: low quality — 620x877, medium — 1240x1754, high — 2480x3508.
A3 format: low quality — 877x1240, medium — 1754x2480, high — 3508x4961.
A2 format: low quality — 1240x1754, medium — 2480x3508, high — 4961x7016.
A0 format: low quality — 2483x3511, medium — 4967x7022, high — 9933x14043.
Autofocus
The autofocus feature optimizes the sharpness of the image when the subject is removed or approached. Typically, the document camera's autofocus works with the touch of a button, but there are also models with real-time autofocus. Continuous autofocus worked well for video recording. Autofocus is especially relevant when replacing documents that are to be digitized. The new document may be thicker or smaller than the previous one, it may be placed deeper or higher. Thanks to autofocus, the camera automatically adjusts the best sharpness, and it does it quickly and accurately.
