Sony A7r III with Canon 1.2 lenses - Aperture error - 1.3

[haring]

Have been using my Metabones Adaptor with the a7R III for Canon EF glasses.
However, I notice that with both the 50/1.2L and 85/1.2L II, both lenses only open up to f1.3, and not f1.2.
I am curious as to why that may be? Is it Metabones problem? Canon's? It obviously does not matter to the images, but I am curious why that may be the case. Anyone?


The lens is fully open but aperture is 1.3 not 1.2.... Anybody has the same problem?

[E.J. Peiker]

Sounds like a firmware issue on the Metabones.

[Bart_van_der_Wolf]

Sounds like a firmware issue on the Metabones.

Could be, and maybe only in the EXIF. The nominal f/1.2 is mathematically f/1.259921 (from 2^(1/3)), therefore rounded to f/1.3 ?

Not sure if one can see any difference between f/1.3 and f1.2 when looking through the lens from the front (entrance pupil).

Cheers,
Bart

[haring]

Could be, and maybe only in the EXIF. The nominal f/1.2 is mathematically f/1.259921 (from 2^(1/3)), therefore rounded to f/1.3 ?

Not sure if one can see any difference between f/1.3 and f1.2 when looking through the lens from the front (entrance pupil).

Cheers,
Bart

Yes, this is it! I It is rounded up!