Paper size
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A4. The document camera allows you to take detailed images or videos of objects (both 2D and 3D), which size does not exceed the A4 format. The physical dimensions of the A4 format are 210×297 mm.
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A3. The operating field of the A3 size is considered the initial for close-up shooting. The physical dimensions of the A3 format are 297×420 mm. The shooting area of A3 format allows you to operate with several documents of A4 format at once. Document cameras of this type are valued for no need to accurately place small 2D/3D objects on the desktop. A fairly large shooting area allows you to automatically recognize any small objects/documents.
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A2. The operating area of A2 format (A2+ or A2++) makes it possible to scan quite large documents. The dimensions of the A2 format are 594x420 mm. The A2+ format is slightly larger — 625×420 mm, the A2++ format is even larger — 660×450 mm. The operating field of A2 document cameras is often equipped with a removable bed for books, which usually provides a recess for the spine. Additionally, the working area of such chambers can be equipped with clamping glass.
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A0. Document cameras with operating area of A0 format are perfect for digitizing engineering documentation, maps, large plans and diagrams. The A0 format is sized as 1189x841 mm. Document cameras have the
...use of high-quality optics with high resolution. The operating area of A0 size usually has a good backlight. Many document cameras also use a clamping glass, as well as various devices to support book spreads, folders and document containers.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.
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.
