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.
Built-in microphone
A microphone is needed to record or broadcast video. Thanks to the microphone, the recorded footage receives audio accompaniment. Document cameras with a microphone are often used to digitize documents with verbal comments by the author. Such devices are indispensable in the preparation of educational lectures and seminars. The microphone is usually built into the document camera. But there are models with support for connecting an external microphone.
HDMI
Document cameras with HDMI interface allow you to broadcast the image to an external display. If you choose this type of document camera, make sure that the HDMI connectors on the camera and the external display are compatible. At the same time, it is important that the interface itself corresponds to the current standard for the camera and display. There are many versions of HDMI. Older versions usually have backward compatibility with newer ones. For example, HDMI 2.0 can unlock the full potential of HDMI 1.2. But when you connect a camera with HDMI 2.0 to a display with HDMI 1.2, the video signal will lose important data packets.
