Ins and Outs of the Nikon Lens Mount.
 

I am starting this thread to deal with the ins and outs of various versions of the Nikon lens mount, and its implications on various models of camera.

Pre Ai, Ai, Ais, D Type, G Type .......... confused? I hope this will help.

Don

Nikon D100, D80, D70, D50 and D40* Lens mount.
 

A little bit of history to start with by way of explanation.
When Nikon upgraded their lens range to AI ( Auto Indexing ) one of the changes to the design was to add an EE Servo Coupling Post. This was added to AI lenses to allow for electronic control, by way of a servo motor, of the lens aperture. This was achievable when using the DS-12 Electronic Aperture Control attatchment on the all mechanical Nikon F2AS.

With the advent of autofocus and advanced electronics in cameras, the option to control lens aperture electronically was taken up. For this electronic control to work, the lens had to be set to minimum aperture, and a means of signalling was required. Nikon took advantage of the EE servo post to solve the problem as it could contact a switch on the lens mount perifery. First used on the F401 it was used on a number of film cameras in particular the F80.

The F80 is relevant as it provided the chassis for the D100 and so it was carried over to that, and subsequently the D70, D50, D80 and in slightly modified form to the D40. As the Fuji S2Pro and S3Pro were based on the D80 chassis it found its way there too.

So what does it all mean.

1) On D type lenses which have a manual aperture control option on the lens this must be set to the minimum for the EE servo post to contact the switch. Unless that contact is made there is no metering and the camera will not function even in manual mode. All changes to the aperture are made electronicaly by way of the mode dial.

2) Although AI lenses have an EE servo post that could be made to contact the switch at minimum aperture, no metering is available as they do not contain a chip to advise the camera of maximum aperture. Hence no metering is available with AI/AIS lenses. For that you have to move to the D1, D2, D3, D200, D300 means of lens communication.

3) Because of the switch proximity to the lens flange, pre AI lenses will not attatch without destroying the switch unless material is removed from the lens aperture setting collar to clear the camera body and the switch.

Images attatched.

1) Explanitory image of the difference between D type and G type A/F lenses.
2) Explanitory image of the difference between Pre AI and AI/AIS lenses.
3) Image of the camera mount to indicate the switch location.
4) Another explanitory of the switch.

Episode 2 covering D1, D2, D3, D200, D300, Fuji S5Pro hopefully tomorrow.

Don

D1, D2, D3, D200, D300, Fuji S5 Pro lens mount.
 

This mount carries over the Aperture Indexing ring from older pro series cameras and does not make use of the EE servo post, so there is no switch on the lens mount perifery.
The AI tab is a solid part of the ring so once again unmodified pre AI lenses cannot be used.

With D type lenses the aperture needs to be set to minimum for metering to work. Aperture is changed by the mode dial. Inclusion of the aperture ring on these lenses is for backwards compatability. They even have an AIS groove that is not used on any of the modern cameras.

The aperture indexing ring comes into its own when using AI/AIS lenses and auto bellows.
With AI/AIS lenses the camera can be used in manual or aperture priority mode with metering. As these lenses do not contain a chip to provide communication of the selected aperture, the AI ring serves that purpose and enables aperture display in the viewfinder.

Don

The Rabbit ears
 

With the introduction of The Nikon F, its first SLR, Nikon introduced the range of lenses to go with it. These collectively known now as Pre AI.
Apart from those lenses that required the mirror to be locked up before mounting, the telephoto's requiring a AU focussing mount, and the big cats, most had a meter coupling shoe ( rabbit ears ). The first meters were clip on selenium units that could be coupled to the shutter speed dial and to the lens by means of the shoe.

Pre AI lenses can be recognised by the solid shoe. When the range was progressivly updated to AI design the shoe was continued in order to ensure backwards compatabilty. AI/AIS lenses had slots in the shoe to let light through to a secondary smaller aperture engraving. This engraving was used to display the set aperture in the viewfinder via a prism.

Mounting of pre AI lenses on the early cameras required that the aperture first be set to f5.6. The lens was then mounted and twisted until it locked. The aperture ring was then turned through its minimum to maximum aperture range to index it with the meter. Oldies will remember that one. ;) With the introduction of AI ( auto indexing ) this was no longer necessary unless an AI lens was used on an old camera with a meter coupling prong.

Of the older manual range, E series lenses do not have a meter coupling shoe but ARE AIS.

The shoe method of coupling a lens to a meter was later taken up by Mamiya with its M645 1000 S in the 1980's. Just as the Nikon F and F2 had seperate metering finders, Mamiya introduced a metering prism finder for its medium format SLR. This was before electronics in the shape of the Bronica ETR, invaded medium format, so a mechanical linkage was needed.

Pics attatched
1) The meter coupling prong.
2) Mounting a pre AI lens
3) Pre AI compatible lens mount

Don

A bit of a bump here specifically aimed at potential e-Bay buyers.

Following Sassans posts of some of the exotica I had a bit of a rummage yesterday while WPF was down. I was really surprised to see some sellers advertising pre AI lenses as compatable with DSLRs. Probable reason for that is a compatability chart I have found in Nikonians that suggests pre AI compatability with D40, D40x and D60. Mind you there is a rider to that chart - ALWAYS CONSULT YOUR CAMERA MANUAL.

Mmmmmmmmmm, puzzled in view of my previous posts in this thread, I downloaded manuals for these cameras, and they are very specific - Pre AI is NOT COMPATABLE.

So my advice is to check that any pre-AI lens has been converted to AI if there is an intention to mount on a DSLR. There are specific exotics from the past that will not fit any DSLR as they cannot be modified - superwides that required permenant mirror lock while attatched, and any telephoto that required an AU focussing unit.

Don

Good thread Don - thanks. Ken Rockwell has a good lens compatability chart that explains a lot

LINKhttp://www.kenrockwell.com/nikon/com...lens.htm#cheap

I find it useful and I agree you need to be careful - back to my packing.

As you posted it Andy I thought I would have a look.

A few things not right at all, or properly explained on that listing.
So I fell off my chair laughing at this statement " Nikon Europe also has another table for DSLRs. I have not checked it for accuracy, but it is crammed with detail and may help you, too. " :D :D :D

Don

Its late Sunday night/early Monday morning, so I can't do it now, but Don please remind me to show you a picture that you may find interesting that is in case I forget it in near future...
(You know about my poor memory and absent mindedness that is all to be blamed to this unfriendly Mr. Alzheimer!

I did not realise that Sassan, so you have our sympathy. :(
I will keep plugging away on our other thread on historic stuff to hopefully give you a lift. Window shopping exotics on WPF :) so no damage to the wallet. :D

Don

Commiserations Sassan - my wife suffers from something very similar due to her MS :( - but it has its pluses - When Nikon Aquisition Syndrom attacks you just say you - No that's my old camera and forget you already have the latest Nikon/Canon/Hasselblad.

Carry on Don - this is great as I am currently looking at Perspective Control Nikkors.