Question on old lenses

The focus ring on these lenses has a small notch, which is placed same distance from the affinity focus level. What is the purpose of this notch?

 

I'm curious as well!

If you mean the one marked with a little orange dot, it is to set and lock the aperture ring at f/16 so you can have aperture controlled by the camera body rather than manually using the aperture ring on the lens...necessary for shooting in the programmed and shutter priority modes. Well explained in the user's manual.

I can't even guess at a purpose for the focus ring notch, unless it is to give a visual reference to approximate focus point. Those early AF lenses often were used on manual focus bodies. I thought I had a few with the small ring, but seems that my older lenses, though pre-D, all have the small rubber focus ring.

Focus by feel?

If you mean the one marked with a little orange dot, it is to set and lock the aperture ring at f/16 so you can have aperture controlled by the camera body rather than manually using the aperture ring on the lens...necessary for shooting in the programmed and shutter priority modes. Well explained in the user's manual.

Nah, not those. These notches marked here....

The notch for a big C Hook Spanner?

I don't have it on any of my similar vintage lenses, but mine are other focal lengths.

The obvious thing that comes to mind is a drive notch for an external focusing system, but I can't see why that would be needed on an AF lens. Since it rotates when the lens is focused, it could drive something else, but I can't imagine what that something else would be. An extensive Google search turned up nothing, save for this thread. Edited August 21, 2021 by conrad_hoffman

a drive notch for an external focusing system

It's not pretty, but guess it could be the locator lug for factory AF calibration?

Haven't found it on my 20+ yr old lenses.

There's no telling. The other thing those all have in common, they're the first-generation Nikkor AF lenses. The subsequent "D" series AF lenses had the more traditional rubberized and pebbled manual focus rings (like the one on the lens that's mounted on that Df) and updated cosmetics. Those first generation Nikkors are most "spartan/cheap-looking" Nikkors ever and Nikon figured that out pretty darn quick.

If you mean the one marked with a little orange dot, it is to set and lock the aperture ring at f/16 so you can have aperture controlled by the camera body rather than manually using the aperture ring on the lens...necessary for shooting in the programmed and shutter priority modes. Well explained in the user's manual.

no that is aperture ring - it is the focus ring and only cut half of the height of the ring

None of my lenses have the notch. I guess the OP's lenses which have the notch also have very narrow focusing ring. So there may be something about narrow focusing ring and the notch.

Maybe Nikon were farsighted and it was part of a focus-pulling system for video. ;-)

 

More realistically, maybe it was so that the user could judge approximate distance the ring is set at by feeling the position of the gap.

Out of just sheer curiosity I googled this over the weekend, assuming I’d see something, somewhere.

 

I found one similar post in this forum asking the same question back in 2007, with no definitive answer, and a similar question on another site in 2012 that generated no responses at all, LOL.

 

I also found no Nikon documentation online from the pre-D AF era that addressed that notch either. Saw more than one image of AF Nikkors that show the notch but with no notation as to what it was for.

 

I think most users were just more than happy to move on to the better ergonomics of the D series and forget those first generation AF Nikkors ever existed. Optically great, but compared to later versions quite cheap-feeling in use, even more so if one was moving from the manual focus AIS Nikkors.

Edited August 23, 2021 by Greg M

Erik’s lenses are top notch. :rolleyes:

Mine are not.

Has anyone actually asked Nikon?

 

I mean it's not as if we're wondering about the notch on a Roman pot is it?

 

The person who designed it is probably still alive!

about a week before I made this thread the question was sent to Nikon, but so far no response. I will of course update this thread if/when a response is received. In the meantime I thank all of you for your comments.

Does the focus ring spin past infinity? I too have been Googling it, would really like to know. I still believe it's an orientation guide to a particular focus point.

Does the focus ring spin past infinity? I too have been Googling it, would really like to know. I still believe it's an orientation guide to a particular focus point.

Hyperfocal distance at a certain aperture perhaps?

I really don't know but the notch is only with lenses that have very narrow focusing ring. I guess perhaps it's there so you can attach a larger focusing ring if you are into manual focusing.

Curiouser and curiouser. The manual of these lenses would most likely describe all the parts of the lens. If no one can locate a manual, there are some on eBay. Do let us know.

Trouble is, if it has no function for the user, it won't even be mentioned in the manual.

 

..and the fact that there are so many venerable Nikon users here that have no clue to what it's for, kinda implies it has no function for the user!

 

But I still want to know. ;)

I have asked Nikon again - different organization :)