Hi Ralf,
I understand there are MANY variables.
The fewer variables that change, the more predictable the results will be. So assume I use the same camera, lens, distance to subject, take the pictures from the same locations, etc. So essentially the only thing that changes is the subject, but the subject is the same size. Lets also say the subject is static.
Surely the accuracy could be reasonably predicted if the only thing that changes is the subject?
What I would like to find out is if I have a human (or house, or baseball etc.) sized object, all other things being equal, what I could expect for accuracy compared to other similar sized objects.
I am NOT asking for the specific amount of error. I would like to know what a reasonable approach to repeatable accuracy would be. Obviously, you can't put everything in a studio under completely controlled conditions. If I am taking photos of houses, I am not going to take the pictures from the same relative positions every time.
So, if you can't take the pictures from the same relative locations, what would be the next best thing to do, ie same distance?