Tamron 46A 70-210mm w/ adaptall-2 for Nikon (D7100)

Texas

Senior Member
My neighbor gave me this (inherited) 30 year old pristine lens a couple days ago and I like its results very much even though it will not win a sharpness contest with something more modern.

It really lets me know how valuable AF is on a camera without a ground glass viewfinder screen. Fortunately the in-focus dot works well on my D7100.

The D7100 is supposed to be happy with AI manual focus lenses, metering properly in A and M modes if you set one of the 9 non-cpu lens slots to know it's max aperture and focal length. My guess is that the focal length parameter is just to help you remember which non-cpu lens it is and to send that data on through to the exif's.

I've set parameter f5 to select aperture by manual use of the aperture ring (which sill meters full open) since the mechanicals of the lens/adapter show that to be the only option that likely makes sense.

There's no highest f-stop lock but the highest f-stop, one past f22, is labeled AE. And yes, I've tried this setting and lots of other things with less success than what is documented below.

I've removed and reinstalled the Adaptall and it and the lens / adaptall / auto aperture lever combo seem to be mechanically fine, very well made as a matter of fact.

The D7100 is the only camera I have that is supposed to support non-cpu lenses so I can't try it on another body.

After fiddling with it yesterday afternoon several things were revealed:
1/ setting the #1 manual non-cpu lens data (correctly) in the menu at f4 causes displayed f stop in the viewfinder to be off by 2 stops. Telling a fib in #1, say f2 causes the display to be closer but not exact as f stops are varied on the aperture ring.
2/ setting this #1 non-cpu slot to different focal lengths doesn't change any of the metering behavior, or anything else noted in this post
3/ Not much luck in A mode but Manual seems to be doing through the lens wide-open (not stop down) metering somewhat accurately - and good pictures can be had by forcing exposure compensation, typically 2 or 3 stops.
4/ Exif's do not get their focal length / f stops recorded at all - blank

My question is: Anybody use Tamron non-cpu lenses with adaptall-2's and get the results promised in the Nikon manual using Nikon models that tout non-cpu lens ability, with respect to metering and exif's ?

Perhaps Nikon non-cpu lenses have a bit more connectivity to the camera than do Tamron's.
 
Last edited:

Texas

Senior Member
Oh, forgot to mention, I've not found a menu item that points to which of the 9 non-cpu lenses that you are currently using. Figure you just leave the menu on the one that lets you specify its max aperture and focal length. The cam only can have one lens mounted at a time so this seems that this menu item may be used to identify the current lens in use.
 
Top