I recently bought a MacBook Air and I am not being able to capture a signature in a white sheet of paper with camera, as it was possible in previous machines and mac OS versions. Does someone have a hint on how to solve this?
When you select the camera on the Preview.app, It should open the camera up. You need keep some distance between the FaceTime camera and the white paper only then Preview.app will pick it up.
- If it's kept too close, the signature will not be picked up.
- keep the paper stable as the camera will not detect if the paper wobbles around.
- Place a light behind the camera shining towards the paper if needed. Strong contrast helps the signature detection.
As other have mentioned in the comments, it really seems to need a lot of light on the paper (probably so it can see the contrast). Much more than you would normally need for doing FaceTime call for example.
Place a strong light source behind your MacBook/webcam (e.g. room light, window, or flashlight) so that its light falls strongly on the paper with the signature. Then slowly move the paper towards the camera.