I have a large object of size 4,5m x 2.5m onto which I want to project AR-Data via solvePnP with high precision. The camera is an iPhone SE 2nd Gen.
Due to the large object size, the camera needs to be placed several meters from the object itself, which I assume will influence the focal length of the camera. Optimally, the calibration is done with the same focal length. Does that mean, I need a chess board of similar dimension, i.e. MUCH bigger than a usual piece of paper?