ray are you using the 'green dot' to manual focus, or just the naked eye? my hesitation on this camera is lack of focus aids...
Hi Tony,
With this lens, I'm mostly just going by eye, but while I'm doing that I can see the green arrows and dot out of the corner of my eye and it seems like my eye and the green dot are always in agreement. Both of my other MF lenses are very wide angle - 14mm Rokinon and 21mm Zeiss - and the DOF tends to be so wide I just check the green dot and figure it'll be close enough - it can also be harder to focus by eye with such deep DOF and more distant subjects. But with this 135, it hasn't been a problem at all.
There's NO electronic connection between this lens and the Df, so I wasn't even expecting the green dot to work. But you create lens profiles for your "non-CPU" lenses, tell it the focal length and the maximum aperture and then the camera will be able to follow your aperture changes and show them to you in the viewfinder and the little info screen on the top of the camera. I guess the focus dot is independent of that, using the PDAF sensor in the camera to calculate focus the same way it does with AF lenses - it just can't move the lens to focus it based on the information, but it has all of the same data coming in. It's kind of funny - the Rokonon claims it contains a Nikon "focus confirmation chip", ostensibly to work with the green dot. The Zeiss doesn't say that anywhere but, like the Rokinon, it has electronic contacts to communicate SOMETHING to the camera. But the 135 AI doesn't have ANY kind of electronics on-board and it seems to behave exactly the same as the two lenses with electronic contacts. The only difference I can see is that I had to enter the data into a lens profile one time with the 135, and I guess I'll have to select the right profile manually if I ever add another non-CPU lens to the stable.
I don't know that I'd buy this camera to use exclusively with MF lenses, but then I wouldn't buy ANY camera to use exclusively with MF lenses. But for having a few MF lenses among the AF stuff, I haven't found it any problem at all...
-Ray
And, of course, if you're shooting something pretty deliberately, you can switch to live view and magnify the hell out of the image, so you can definitely fine tune focus with that if you're not happy with your eye or the green dot.