The digital calibration is used to create a reference dataset. It needs to be performed only once, as long as nothing moves. If one camera gets displaced, you’ll to start over.
A calibration bar or panel is essential in order to have a reference on which you’re going to aim all of your cameras at (pre-calibration). It is also going to be used to apply digital calibration to smooth out all imperfections. The back-lit calibration bar is great for a full-360 setup or a large setup where you need all cameras to see the exact same markers. For 18 cameras or less, you can get away with a calibration panel which is way easier to use. It is recommended to have your markers as close as possible to the top and bottom edges of the frame (but keep them in the frame). Buy on xangle.store
Place all of your cameras on your structure and aim at your calibration bar. Try to be as precise as possible to avoid too much cropping after the digital calibration is applied. Use either the live view at the back of the camera or the live-view in Xangle to perform the pre-calibration. In both cases, use the grid to line-up with with the markers
From Xangle, navigate to the Calibration module and take a reference shot (trigger). The purple box is the common detection zone for all cameras. Make sure the markers are always inside these boxes on all frames. The blue box is for the markers, thus, this one is different from one camera to another. In ideal situations, you’ll never have to fine-tune the blue boxes. In cases where you have a bright window behind your calibration bar, it can help to manually place the blue boxes. To apply the manual calibration (blue box adjustments), click on “regenerate”.