I'm trying to accurately measure the size of objects via photogrammetry. The objects are 1 to 2 feet from the front of the camera lens, so where I start measuring from makes a difference.
I think the proper distance measurement is from either the "nodal point" or "entrance pupil" of the lens. Is that correct? I'm not even sure if there's a difference between the two for a non-zoom lens.
Which is the proper measuring point? And how to figure out where that is on the lens?