I always get intimidated every time I look at my Nikkor lenses and cannot make out what the heck are all those acronyms for. For example, on my primary carry-around lens, the Nikkor 18-200mm VR, this is what it says:
AF-S NIKKOR 18-200mm 1:3.5-5.6 G ED DX
I can kind of guess what "AF" is, and maybe the "S." But what the heck are "G", "ED", or "DX?" The same goes for my other two lenses. Now I'm kind of lost on what all these alphabet letters mean and how they help (or hurt) my photographic ability. So, I'm on a little quest to find out what these acronyms actually mean and if they have any use (I'm pretty sure they do). Otherwise, Nikon wouldn't bother to place them there. To make matters even worse, photographers also like to add even more confusion to the already-confusing world with slang. Pre-AI anyone?
One of my favorite photographers (and a fellow Nikonian), Mr. Thom Hogan wrote a very detailed article - complete with a historical lesson about what these codes mean. But since my brain cannot process all the detailed info that Mr. Hogan wrote, I decided to come up with my own Idiot's Guide to Nikon Lens Acronyms. This is definitely not a complete list since I don't need to know them all - just the modern acronyms that appear on everyday lenses (and especially my lenses).
| Acronym | What it means | Meaning for me |
| AF | Auto Focus | This makes things look sharp. :P |
AF-I
(replaced by AF-S) | Auto Focus Internal | Same as AF, but the motor is internal. Used by long telephoto lenses and tend to be quite noisy. I can hear the grind during focusing. |
| AF-S | Auto Focus Silent | Focus quietly and silently. Quite an important feature when shooting wildlife. |
| AI | Auto-Indexing manual focus with light meter. Old school lens. | Some of the AI lenses are legendary due to their excellent optics. These were the lenses before autofocus was conceived. |
| DX | Lens which is designed for DX format sensors (not full frame). | Almost all Nikon DSLRs are DX format (D40, D40x, D50, D60, D70, D70s, D80, D100, D200, D300). The only exception is the new Nikon D3, which is full frame (FX). |
| ED | Extra-low Dispersion | High-quality glass to help reduce chromatic aberration. |
| FX | Lens which is designed for a full frame camera. | Meant for Nikon D3 pro DSLR. |
| G | G lenses do not have manual aperture control ring control. Aperture can only be controlled from the camera body. | Must set camera to Aperture mode to control it manually. |
| IF | Internal Focus. All focusing is done internally in the lens. | The front element of the lens does not move. |
| VR | Vibration Reduction. Reduce camera shake. | Not to be confused with Virtual Reality. |
| VR-II | VR version 2 | Latest and greatest VR. |
| Micro | Used for macro photography. | Nikon just wants to call things differently than the rest of the field. |
This Wikipedia entry actually has an even more detailed listing of most of Nikon's lens acronyms. Very useful if you need to know more than what is listed here.
So, back to the AF-S NIKKOR 18-200mm 1:3.5-5.6 G ED DX lens. From the table above, this means that the lens can AutoFocus Silently (AF-S), has no manual aperture ring control (G), is made up of high-quality glass to reduce chromatic aberration (ED), and is made for a DX sensor (DX).
Now I know.
-Chan
