« on: January 05, 2013, 02:00:52 PM »
I have noticed by looking at the patents that we see detailed here on Canonrumors.com sometimes that the REAL focal length and the REAL aperture are not the same as the MARKED focal length and MARKED aperture.
What I mean is you see a patent for a 50mm f 1.4 lens and the details on the patent will say something like it's really a 51.2 mm and f 1.51. (not real numbers here, just an example I made up)
So maybe "70" on the 24-70 is really 68.2mm and "70" on the 70-200 is 73.1mm.
Don't know this for sure, just something I have seen from the patents and am speculating on.