Diagnose black video, permission errors and poor image quality in the right order.
The most common causes of a black image
If the camera test does not open, first make sure the physical privacy shutter is open. Then check the site's camera permission in the browser. Some cameras can be used by only one application at a time, so Teams, Zoom or the camera app can prevent the browser from receiving video.
- Check the privacy shutter and camera key on the keyboard.
- Close other camera applications completely.
- Change the browser permission from blocked to allowed.
When the image works but quality is poor
The stream resolution reported by the browser may be lower than the camera's advertised maximum. Lighting, power saving, the USB connection and the profile selected by a call app all affect the real resolution. Place the camera near eye level and light your face from the front.
DeviceDoctor reports stream resolution and frame rate as seen by the browser. These are not the sensor's hardware maximum; they are practical readiness indicators before a call.