How to evaluate camera calibration quality?

What I need is an objective measure for novice users. I would imagine it as an average reprojection error for chessboards that fill the entire image as much as possible. So sometimes it can be a single image (for narrow lenses) and sometimes it must be a number of images for wide-angle lenses. I am just thinking aloud. Say, I took 500 images, randomly split it into 5 batches and performed 5 calibrations. Which one is the best?