Tamron 24-70 G2 at f/3.2
When stopping down from 2.8 to 3.2 my copy shows great improvements in contrast and sharpness, but I noticed that it also underexposed by about 1/3 of a stop when compared to 2.8 and 3.5 (these expose correctly). Also, bokeh gains a lot of definition between 2.8 and 3.2.
On my 70-200 G2 the change in quality between 2.8 and 3.2 at 70mm is very subtle, but it's quite extreme on the 24-70.
My aperture blades are moving properly when changing aperture, but it seems like the they close quite a lot when changing from 2.8 to 3.2.
Does anyone else's copy show a great increase in sharpness, loss of bokeh, and underexposure when stopping down? Only at 3.2.
I'll post some samples tomorrow when I have time, sorry.