I have worked out how to calibrate three cameras but I am having issues calibrating four. The last theory I tried out was holding the maglite facing camera one and going through the usual motions. The maglite was visible in Cameras 1,2 and 3 but not in Camera 4. So I then turned to camera 4 and went through the same sort of motions. This does not seem to help, I keep getting minus readings for camera fours height after calibration. Do you have any tips for calibrating a four camera set up. For example what path to do, where to face etc?. Thanks in advance for your help.

Current version of iPi Studio can only calculate calibration if marker is visible in all cameras in 70% or more frames. This is usually not a problem in half-circle camera configuration but can be a problem in full-circle camera configuration. We are working to resolve this issue in upcoming versions.

As a temporary workaround, I recommend that you install 4 cameras in half-circle configuration. A 4-camera system has higher accuracy and reliability then 3-camera system even if cameras are installed in half-circle.

That makes sense, I was wondering why I could not get it to calibrate. Thanks for the advice I will try the half circle with four cams.