Make sure the document is not too close to the camera lens.
If the document has repeated detailed patterns, such as horizontal stripes and checkered patterns, the auto focus may not be able to focus. Try placing a different document under the camera lens while adjusting the focus.
Press the Focus button.
If you’re using a projector to display the image, check the focus on the projector.
Make sure the document camera (or projector) lens isn’t dirty. To remove dirt or smears, use lens-cleaning tissue. If necessary, moisten a soft cloth with lens cleaner and gently wipe the lens surface.
Caution: Be careful not to scratch the lens. Never rub the lens with abrasive materials.
Make sure the lens is not fogged by condensation. If you’ve just moved the document camera (or projector) from a cold environment, wait a couple of minutes before using it.