How can I measure the actual Aperture of a DSLR lens ? I know I can divide FL by F # and get the theoretical aperture. But having dealt with telescopes all my life, it just really bugs me that I do not know the physical aperture of primary lens.
I know the physical aperture will be pointless because Iris changes accessible aperture - but I still wanna know anyway. For a start, I do not even know if the glass in the front is the actual lens ? Like a telescope, can I just put a tape measure against the front element of DSLR lens and take that as the actual aperture? If not, then how ?
I'll really appreciate some input. Thanks.
Edited by Agreegator, 13 April 2021 - 03:19 AM.