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Identifying Used Camera Equipment, Part 2 – More Lenses

Do you have used equipment to sell? Green Mountain Camera is interested in purchasing your used or unused equipment. Find out how to sell your used equipment here.

In this part of our series of identifying used camera equipment we are tackling a topic that will help a lot of confused people--Nikon lenses.

Over the years Nikon has made a lot of lenses. In fact, to date, Nikon has manufactured over 50 million lenses. And, with 50 million lenses floating around out there, we come across a lot of used Nikon glass. Most of the used Nikon lenses we see are "classics"--of the manual focus type, and these come in three main varieties. The three main types of Nikon manual focus lenses are pre-AI (often referred to as non-AI), AI, and AI-S.

This is where most people get confused. What are the differences between a pre-AI, AI, or AI-S Nikon manual focus lens, and how can one tell the difference? Perhaps it is easiest if we first answer the second part of that question. Identifying the difference between the three main types is actually pretty easy, as long as you know what to look for...

Nikon pre-AI LensNikon AI LensNikon AI-S Lens
Can you tell the difference between these three lenses that would make the first pre-AI, the second AI, and the third AI-S? Here's a tip: focus on the mounts.

Nikon pre-AI Lens


Nikon AI Lens


Nikon AI-S Lens


In the above photographs are marked the areas of concern. As you can see, the pre-AI lens has a smooth mount surface. The AI and AI-S lenses have ridges of metal (painted black) sticking out from the lens mounts, and with the AI-S lens there is a small, rounded indentation in the mount. In addition, the smallest aperture number on the lens is always colored orange. You may have also noticed that the pre-AI and AI lenses have a notched piece of metal in the shape of an inverse V adjacent to the mount. Really, that is all there is to identifying the differences between the three types of lenses.

So, now that the differences have been pointed out, what do they do?

Pre-AI lenses where manufactured from 1959 to 1977. The inverse V looking piece of metal on the top is actually the meter prong. This prong mates with compatible cameras, like a Nikon F with Photomic finder, and as the aperture is changed on the lens, the prong "communicates" the aperture setting to the camera. These lenses were never intended to be called pre-AI from the get-go. In fact, they were referred to, simply as, Nikon F lenses. But, once AI lenses were introduced in 1977, this is how these lenses were referred to by people.

It's probably a good time to note that it is not appropriate to mount pre-AI lenses on Nikon AF camera bodies (including digital, but excluding the D40, D40x, D60, D3000, D5000) as these lenses may damage the cameras.

Auto-Indexing (AI) lenses were introduced in 1977, and have an AI ridge for meter coupling--that ridge is the piece of metal stick off the mounts in the above pictures. Having a ridge instead of a prong for meter coupling makes it quicker and cause for less error to mount and unmount lenses. AI lenses, you will notice above, have a second row of aperture values. These values (also called Aperture Direct Readout) can be seen in the viewfinder of compatible cameras, so you know what aperture is being used without taking your eye away from the finder. Nikon began multicoating lenses in 1975, so these lenses are almost all multicoated. Also, Nikon continued to add the metering prong to many of these lenses to maintain meter coupling with older camera models.

Unlike pre-AI lenses, AI lenses are compatible with almost all Nikon camera bodies after 1977, except for a few of the cheaper AF camera bodies. Also, it is interesting to note, Nikon offered AI conversions for pre-AI lenses. These converted lenses look very similar to AI lenses, and most people can't tell the difference and often refer to them as AI lenses, instead of AI'd (AI'd is the appropriate term). There are also many do-it-yourself lenses out there where individuals converted the lenses themselves. We have even seen lenses where someone super-glued a little plastic tab in the right spot on the aperture dial to couple the meter correctly.

In 1981 Nikon introduce auto-index shutter (AI-S) lenses. These lenses have the small indentation in the mount of AI-S lenses as seen in the above pictures, and this indentation serves the purpose of indicating that a lens with a linear action diaphragm is mounted. The Nikon FA was the first camera to use this information, and that happened back in 1983. It is interesting to know that no current production cameras use this information. AI-S lenses do feature modifications to allow for more accurate shutter priority and programmed exposures, but only when used with a compatible camera body. Also, AI-S lenses are typically lighter and smaller than the AI or pre-AI lenses. Many individuals attribute this to Nikon's motivation to cut costs rather than innovative construction materials. AI-S mounts typically feature 3 screws rather than 5 (see above pictures).

This concludes the second part of our series about identifying used equipment. In our next post we will talk about identifying cameras. As there a many different types of cameras, and hundreds of manufacturers, we'll discuss the main camera types like SLR, rangefinder, etc., rather than more specific things like identifying different Leica rangefinders (IIIb vs. IIIf for example).

Do you have used equipment to sell? Green Mountain Camera is interested in purchasing your used or unused equipment. Find out how to sell your used equipment here.

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