# Pre-Ai lens?



## g-fi (Aug 7, 2011)

So, I have been trying to purge some of my gear that I no longer use, and as I went around listing my lens various places, I listed a 24mm and 50mm AiS lens here in the Buy and Sell forum. This evening I get an inquiry from a forum member and after a bit this member says that with his research, he believes that my 50mm AiS lens that I have listed is actually a pre-Ai lens due to the markings on the front of the lens. This baffles and confuses me because I have USED this lens on my D50, I know without a doubt that it mounts to my camera with no issues. A little bit of history on this lens, it's one that was passed down to me from my father who was an amateur astronomer in his college days, he was the original owner of the lens so I didn't purchase this lens from another seller thinking it was an AiS lens. In researching the pre-Ai lens, I notice that the markings on MY lens do match most of the markings on all the reference pictures of the pre-Ai lens. (Namely, the Nikkor-S Auto wording), but my lens is absent the "Nippon Kogoku Japan" markings. The mount DOES appear to be identical to the pre-Ai mounts, and everything I have read says that the pre-Ai mounts will damage a modern dslr. Now, confused, I took the lens out of its bag, and MOUNTED IT TO MY D50. Then I took *this* picture:




DSC_0159 by G-Fi, on Flickr

Here is a picture of the lens mounted to my D50: (camera is in manual, 1/30, f/11, before the above picture was taken, picture above was taken at f/2.0, 1/45)











So... what's the deal? I have a hard time imagining that my dad had this lens modified as all the websites I've read said that you have to in order to mount it to a modern dslr, but I don't know for sure as he passed away before the gear was given to me. The lens mount doesn't appear to be modified at all. Have I been playing Russian roulette with my camera every time I've used this lens and not been aware? I haven't used the lens much as almost immediately after I got this set of gear, I purchased a 50mm 1.8 AF and I'm lazy and prefer my autofocus. BUT, I have used it!  

I'm leaning towards the dumb luck theory, that somehow despite everything saying it should damage my camera, it simply hasn't, because it appears to mostly be a pre-Ai lens. I am putting myself in photographers time-out for assuming that since it mounted, and worked, and I never really looked very closely at the lens, that it was an AiS lens. I'll be relisting it as a pre-Ai lens since apparently people still want them, I'm just kinda dumbfounded and a little embarrassed.





DSC_0148 by G-Fi, on Flickr

The offender




DSC_0149 by G-Fi, on Flickr


----------



## JG_Coleman (Aug 7, 2011)

I've used the same lens on my D5000 before without any problem, at all.  However, I should point out that while my lens looks NEARLY identical to yours, it does have the "Nippon Kogaku Japan" marking.

This had been quite a dilemma for me originally, since I had been messing around with this lens on my D5000 for a month before I found a forum post somewhere in which somebody was advised to check a compatibility chart before putting older lenses on their newer digital body.  Luckily, almost all the charts said it would work fine on the D5000.

Unfortunately, many of the same charts seem to insist that you could damage your D50 by putting on this lens... some charts claim that it won't fit at all (?).  I did find a couple charts, however, that claim that it will fit on your camera just as well as it fits on the D5000.

So.... what have we learned here?  That the people that make these charts clearly don't do so from experience.

I did find this post -Non AI lens on D50? - PlanetNikon Forum- where some guy claims to know why non-AI lenses ARE compatible with the D50.  But, then again, the proliferation of contradictory compatibility charts all over the internet doesn't speak too highly of the knowledge possessed by the general public on this issue.


----------



## Derrel (Aug 7, 2011)

The Baby Nikons, as I call them, will MOUNT  ANY NIKKOR LENS!!!!!!! However, the D50 is NOT, I repeat, is NOT a member of the newer, Baby Nikon Family of D40,D40x,D60,D3000,D3100, D5000, D5100.

ANd YES, that lens is definitely, 100 percent, without a doubt, what is now called a "pre-Ai" vintage lens....its a Nikkor-S Auto, which is simply put, pre-Ai.

Your photos do not show the most-critical area, which is the back edge of the aperture adjustment ring; that ring on "many" older, pre-Ai Nikkors, is somewhat large in diameter, and can damage the minimum aperture sensing lever on several d-slr bodies; the minimum aperture sensing pin is located at around 7 o'clock, at the bottom, left of the lens mount area; that is a CRITICAL part of the Nikon metering system. It tells the camera that an attached lens is set to minimum aperture, and also what the minimum aperture "is".

The D50 HAS a  minimum aperture sensing pin; the Baby Nikons do NOT HAVE this part!!! THis lens probably really ought not to be used on a D50 (nor on a D200 nor a D300), but it is 100 percent fine, perfectly, 100% fine, on a D5000. (the minimum aperture sensing pin is not to be confused with the Automatic Aperture Indexing follower, located at 2 o'clock on the lensmount periphery.)


----------



## g-fi (Aug 8, 2011)

I don't care what anyone says Darrell, you are a priceless fount of technical information. Thank you guys! 

Its awesome that the pre-ai glass works with so many bodies, it really is a nice little lens. 

And I heart my Baby Nikon! Until I have enough for my Big Girl 3Ds, it will get me through. 

Thanks again!


----------



## epatsellis (Aug 8, 2011)

A few things to consider:

Anytime you see a solid coupling fork, assume it's a pre-AI. While some conversions retain the solid fork, it makes it difficult to see the ADR numbers (Aperture Direct Readout) as no light falls on them. 
The appearance of the Nikkor Branding and lens element count, e.g. my 55 1.2 Nikkor S-C (see Grays of Westminster Glossary: Early Nikkor Lens Designations), implies that it started out as a PreAI lens, but in my case, the lens was factory converted to AI, indicated by the ADR indicators, the later version coupling fork and the existence of the EE coupling. 

The last series of lenses, AI-S, can be differentiated by two main physical differences, the minimum aperture on both the ADR and larger numbers are orange, and there's a scallop cut into the mount near the locking slot, see the attached image with the area circled (sort of) in cyan. AI-S lenses have a linear stop down action, as opposed to the non linear action of the earlier lenses, allowing the camera to set the aperture in program mode, it is the same approach used to set aperture in AF lenses as well. The area marked in red is the AI coupling ridge.

Regarding modifications, if the aperture ring has been filed, assume it's at least a minimal AI conversion, though it probably will lack the minimum aperture post (also known as the EE servo, see area in attached image circled in yellow), as few modifiers actually add one, see: Precision AI Modification. There are numerous Pre AI lenses that were factory modified (by exchanging the aperture ring for another), these have all the functionality of an AI lens, and are typically priced more than an Pre AI, but a little less than the same native AI lens, though some seem to be far more valuable. A good reference for the inexperienced is Thom Hogans page here: Nikkor Lens Technology and Lars Holst Hansen's page here: DIY Nikon AI modification






I hope that helps, as while the F mount hasn't changed per se, everything around it has to encompass the newer technologies.

I've added this image: 




which shows clearly the ADR and AI tabs.


----------



## Garbz (Aug 9, 2011)

epatsellis said:


> A few things to consider:
> 
> Anytime you see a solid coupling fork, assume it's a pre-AI. While some conversions retain the solid fork, it makes it difficult to see the ADR numbers (Aperture Direct Readout) as no light falls on them.



That first part is a bit counter intuitive. I have seen far more AI and AI-S lenses with coupling forks than pre-AI lenses with AI modifications. Many of these aren't conversions, early AI and even AI-S lenses have coupling forks on them factory fitted.


----------



## epatsellis (Aug 9, 2011)

Garbz, there is a progression of coupling forks, 4 different versions have existed. The image below (from the mir.com nikon site) shows them from left to right, oldest style to newest. The two to the right are AI type forks, note the holes in them to allow light to shine on the ADR numbers.






When I said "solid coupling fork" I meant one of the two on the left, as opposed to the ones with holes in them, which are the AI/AIs style.


----------



## imagemaker46 (Aug 9, 2011)

Not that this will answer the question, which has already been answered.  I have an old Canon 400 2.8FD lens, it is pre auto, I also have the adapter that Canon made for a little while to use it on the EOS bodies, which I have also been using on my 1D bodies, what I do end up with is a 620mm 3.2  with better glass than the newer 400 2.8.  If the lens fits use it.  The older glass has some great qualities.


----------



## Garbz (Aug 10, 2011)

epatsellis said:


> When I said "solid coupling fork" I meant one of the two on the left.



Ahhh thanks for the clarification. You're right on the money with that.


----------



## djacobox372 (Aug 13, 2011)

It is very common for these lenses to be converted to ai, but yours appears to be original.


----------



## BOMAX (Dec 22, 2011)

I am an amateur , my disclaimer is that I may be right or wrong but   never intend to offend any Human...or alien,animal, rock, tree or tree   huger, lumberjack or so on. I just own a Camera or two and have learned a   HUGE detail that I kinda already knew that led me to buying a D50 when   they came out. That huge thing was ...taking 'the' picture. Meant:   anyone can take a picture...but no one can teach you to take "*The*"  picture. At 50 I have witnessed millions of pictures. Very Brief , I  was a Disney Character for 25 years full time...not anymore. Yeah...I  got stories about Cameras and people  

I have not digressed because I needed to start...I just got ahead of myself.

I have a D50...I have *RACKED MY BRAIN* for 2 months about this topic. Quick answer... I have a similar Lens.

NIKKOR-S Auto 1:1.4 f=50mm Nippon Kogahu Japan no.613243 

This Lens mounts fine ...perfect...No binding...not a clue of any damage.
The old Nikkor has the pointed solid coupling fork.

My old Vivitar series 1 90mm No.37###### has a solid fork...Series 1 70-210mm No.22####### has a  solid fork...Series 1 28-90mm No.28###### has a open 
fork...and my Vivitar 85-205mm No.22######(  bought to learn to dismantle) has a solid fork.


I just do not see a problem. The oldest 50mm has a black metal ridge  next to the glass, but that does not interfere with anything either.  Taking shots using these manual lenses has changed my photo experience  to FUN. HDR has made that fun "art"...The D200 I had, mounted these  Lenses  just fine and in fact showed them how to really show off their  stuff. I almost had my lenses altered...but not yet. I want to see how  they will mount to a newer Nikon after the D7000. I am more than pleased  with the D50...loved the D200 but sold it for profit and wait...if I  spend money on a new Nikon again , it will have to have 60fps in the  video and hopefully 9 brk.

HDR Note: I look at a picture as a  song and each shot as a musical note...the camera can make wonderful  notes one at a time. However , post editing is something I have learned  that is necessary to elevate your pictures. This example may help  another amateur understand that a camera can take  many notes of the same photo but combining the notes the camera sings  your beautiful song. 
Below is a simple picture I took to show my brothers what I was talking about. The the first is the note, the second is the song.


----------



## buggz (Jul 19, 2015)

g-fi said:


> DSC_0148 by G-Fi, on Flickr
> 
> The offender
> 
> ...



This is an F mount PRE- AI.

Look here  :   http://www.photosynthesis.co.nz/nikon/serialno.html#50fast

and check your serial number.
It is S-Auto Nikon with serial 1,062,569


----------

