I'm using a checkerboard or circles to use solvePnP. In this case, how many pictures do I need to prepare? Only one picture is fine because it includes several points? I saw some articles recommend to use at least 10 pictures for calibrateCamera, but no articles say anything about solvePnP.
Also, I noticed that the latest calibrateCamera in OpenCV3 accepts the object points in the object points' coordinate frame (= checkerboard coordinate frame), and not necessarily be in the world frame. Is it the same for solvePnP? Or do I need to have the exact 3d pose for the different checkerboard images if I change the angle?