A 1/2.3-inch or 1/2.5-inch CMOS sensor is standard. Larger sensors (like 1-inch) offer better low-light performance, but for document cameras, a good quality 1/2.8-inch sensor with Sony STARVIS technology is the gold standard for clarity.
High resolution requires a lot of light. Cheaper sensors in budget 4K cameras can produce "noise" (grainy specks) in dimly lit rooms. Look for cameras with larger sensors (often measured in inches, e.g., 1/2.8") which perform better in variable lighting conditions. Some models come with built-in LED lights to illuminate the subject, which is crucial 4k document camera
Compare this to the previous standard, 1080p Full HD (1920 x 1080 pixels). A 4K document camera offers four times the pixel density of a standard HD model. Cheaper sensors in budget 4K cameras can produce
Many modern document cameras are also "PTZ" (Pan, Tilt, Zoom) devices. In 4K, you can aim the camera at a whiteboard 15 feet away, zoom in on a specific equation, and still read it clearly. Standard cameras force you to choose between capturing the whole board (tiny text) or a section (blurry text). 4K captures the whole board with enough data to crop later. A 4K document camera offers four times the