What’s the difference between a lens with ED, G or D in the description? This article spells out what the major letters are that Nikon uses in describing it’s lenses.
What do all the letters mean
So you’re out looking at lenses and they have an alphabet soup of letters after the focal length, what do they all mean!? Well here is a short list of what they mean in plain English
AF: AF simply stands for auto focus, a lens with this designation will work with Nikon camera bodies auto-focus motor to focus the lens automatically.
AF-S: This designator stands for Auto-focus Silent wave motor. This means the lens has a focusing motor built in that operates on a principle of sound waves in a fluid. What this means is that the lens will focus without using the focus motor on the camera body. The focusing is usually much quicker (especially on a D70 or D50 body), almost silent focusing which is good for chapels or other places you may not want to make noise. The downside to this technology is it often results in a larger heavier lens.
ED: This stands for Extra-low Dispersion glass. This means that one or more of the lens elements is made from a very high quality, very expensive, glass that has very low chromatic dispersion. A lens with this marker should give a sharper and more accurate color representation than a lens without it.
D: The D is for Distance. A lens with D means that the lens will send distance information to the camera body. The body then uses this information to help with it’s metering.
G: G lenses don’t have an aperture ring on the lens, meaning the aperture can only be set from the camera body. This is fine since all current Nikon bodies can set the aperture.
DX: DX is for digital. When you see this it means the lens was designed to work with digital SLR cameras. Digital SLRs have a smaller sensor size than the equivalent 35mm film size, DX lenses take this into account and can be made smaller and cheaper than an equivalent full frame lens. The downside is that it can’t be used on film in the full zoom range, and it is always possible that Nikon will switch sensor sizes. (although they have said they are dedicated to the DX sensor size.
IF: Internal Focusing: This means what it says, the elements that move to focus the lens are internal, you won’t notice anything moving on the outside when the lens focuses. Many of the Nikon lens use this technology today, a few like the micro lenses don’t.
VR: Vibration Reduction. A lens with VR has a built in gyroscopic stabilization system. These gyroscopes actually move one of the lens elements to help compensate for camera shake. Nikon claims that you can hand hold a lens about 2 stops slower than you could without VR. In my experience this is sort of true. If you are taking a picture at 200mm in a lower light situation and with no VR you get 2 good pictures out of 10, with the other 8 showing lens shake, then with VR you may get 4 or 5 good shots with the others showing lens shake. So it improves your odds, but isn’t a magic bullet.