Zeiss Vario Sonnar f3.3-4.0/28-85mm max aperture

[edwardkaraa]

Anyone knows what is the maximum aperture at different focal lengths settings?

Normally, it should be f/3.3 at the minimum zoom extension, in this case 85mm, and f/4 at the maximum extension, in this case f/4. Is this correct?

Curiously, Zeiss MTF sheets show f/3.3 at all focal lengths: 28, 50 and 85mm. Isn't this lens supposed to have a variable max. aperture?

 

[Jman13]

The lens is variable aperture with f/3.3 at the 28mm end and f/4 (or very close to it) at the 85mm end. You can see the viewfinder darken as you zoom to 85mm. I believe it is continuous aperture change throughout the zoom range. The reason I say it is probably just CLOSE to f/4 at the 85mm end is that I can see the aperture still stop down a smidge when selecting the f/4 spot on the aperture ring, even at 85mm. (At least, I assume it's f/4 at the unmarked detent between f/3.3 and f/5.6 on the ring).