is it a AI or a Non AI Nikkor?

<p>Hey guys, i have recently bought a used Nikkor Q Auto 135mm f3.5 lens serial number 742556 (if it helps) and i need help to determine if it is Ai or non Ai. i am going to use it on my D200. i was checking some websites for determining this and i found this webpage having an image of the same lens as i have it and it shows its AI, the link <br>

http://www.lezot.com/servlet/the-83/Nikon-Nikkor-lens-conversion/Detail<br>

i have a few images below of my lens and the mount, if some of you guys here on the forum own this lens and can help me figure out if this is an AI or a non AI lens it will be great as i dont want to risk putting it on my D200. </p>

<p>i also saw many other pages regarding the same information and it mentions to make some modifications to the the AI ring, but all those examples are from the normal and wide angle primes, i never see any telephoto examples or in specific this lens. <br>

in case if you guys wish to see any more detailed or specific part of the mount please do let me know and i will post that image as well.</p>

<p>thank you...</p>

<p> </p><div></div>

<p>It was a non-AI (F) mount that was shaved down and is neither. On an Ai lens the part of the aperture ring facing the camera would not be smooth. There would be a protrusion that would link with the coupling ring on an Ai camera</p>

<p>This lens only works as a manually stopped down lens</p>

<p>As John noted, this lens has been modified by completely milling the rear skirt of the aperture ring. As such, it can no longer be readily* converted to AI to allow for open aperture metering, as the material necessary to create an AI ridge (and EE servo post) on the rear of the aperture ring has been completely removed.</p>

<p>It is however safe to mount on your D200 and any other modern body, but stopdown metering is now the only option.</p>

<p>*(The only way to AI convert this lens is to replace the existing aperture ring (factory kits are no longer available) or add a post by some means to the rear skirt of the aperture ring.)</p>

<p>There are some 135mm F3.5 NikKor-Q serial number blocks that nikon NEVER ever made a factory AI kit for; ie the "orphaned Nikkors" as we called them in the late 1970's and early 1980's. These lenses sold cheap in this era 30 years ago and are mostly lenses made before say 1967.</p>

<p>A factory AI kit was never made for your lens.</p>

<p>As far as a non factory AI mod; some lenses made before 1967 have nothing to machine; some do. Here I AI modified my 5.8cm F1.4 I got used in 1962.</p>

<p>It's unfortunate that that lens was milled all the way down, but if you really really want to make it work with AI it might still be possible, though not as easy as it would have been to mill it down correctly. Here, for example, is what I did to my Vivitar 20 mm lens, whose aperture ring does not go far enough back to engage the AI tab. It's just a little piece of brass, held on by the single screw that attaches the meter claw. A two screw claw might hold it better. If you don't worry about the cosmetics of an already spoiled aperture ring, you could also, if so equipped, mill a little slot on the surface of the ring, and screw a tab directly onto it.</p><div></div>

<p>Unless you activate your camera's depth of field preview, this particular lens will always "tell" your camera that it is set to F3.5, regardless of the f stop in use.. The ring that is missing, contacts a small spring loaded lever on your cameras lens mount. This allows the body to know what aperture the lens is set to, without having to stop down. AI, stands for "auto indexing". Which is a what the lens and body are doing.</p>

<p>You can shoot it, and stop down to meter. Or you can look for another Nikkor that's AI, or that's been AI'd. I have to assume you didn't pay very much for the 135/F3.5? Which is actually a decent lens even wide open, but becomes a great lens stopped down a few stops.</p>

<p>thanks guys i have figured out from all your suggestions what has to be done to the lens. it helped me find a solution the AI ring is actually proper and i have to mill a little part from it (image below). i tried the AI ring on the camera body and how it stops down when it is rotated. as i am a digital kid, this is my first ever experience with the NON AI lens and i have completely understood how it works. thank you for all the suggestions and inputs. Appreciate it.</p><div></div>