1. Lens Nomenclature
Looking at a Nikon lens and trying to decipher what all the letters and numbers mean can be an exercise in frustration. As you can see in Figure 1.1, there is a lot of code on the lens. If you know what you are seeing, it’s easier to pick the right lens. Think of the following as your decoder ring to the Nikon lens system.
Figure 1.1 The AF-S Nikkor 18–55mm f/3.5–5.6G DX lens. Sounds great, but what does that all mean?
- mm—The focal length (or focal length range) of the lens in millimeters. Prime lenses have a single number; zoom lenses have two numbers showing the focal range.
- AI/AIS—In 1977, Nikon introduced a new coupling system called “Automatic maximum aperture indexing,” or AI. The AI lenses were followed by the updated AIS lenses, allowing for more precise control over the aperture by the camera. These are manual focusing lenses that allow you to meter with the lens wide open; the camera changes the aperture to the set value when you take a photo. AI/AIS lenses mount on any Nikon camera, but you will need to focus them manually.
- E—The Nikon E-type lenses were budget lenses created for lower-end film cameras. These lenses were usually made of plastic and not as durable as the higher-end lenses.
- D—The D-type lenses can read the distance from camera to subject. The camera then uses this information to get better exposures by a flash.
- G—The G-type lenses have no aperture control ring and are for use on cameras where the aperture control is solely on the camera. They cannot be used on older cameras. These lenses also have the same distance-reading capabilities as D-type lenses and transmit information to the camera so flash power can be adjusted for the best exposure possible.
- AF-I—Auto Focusing-Internal lenses were the first autofocus lenses with built-in motors. This technology was built into the super-telephoto lenses. There is an electronic connection, not a mechanical one, between the lens and the camera to control the autofocus. All the AF-I lenses are also D-type lenses.
- AF-S—Short for Auto Focus-Silent Wave Motor, AF-S lenses are autofocus lenses equipped with the Silent Wave Motor (SWM). These lenses were first introduced in 1996 as an update to the AF-I lenses. The motors in these lenses allow the photographer to adjust the focus manually even if the motor is engaged. AF-S lenses work on the entire line of digital SLR cameras. While the AF-S technology was originally only in the more expensive lenses, it is now used across the Nikon line of lenses.
DX—The DX designation means the lens was created for cameras with the smaller cropped digital DX sensor. Designed in 2003, DX lenses have fairly wide focal lengths to help negate crop factor. For example, the widest regular lens available before the DX lenses was the 17–35mm f/2.8, which cost close to US$2,000 and still gave a pretty normal 26–50mm view on the cropped sensor. The first DX lens, the AF-S DX Zoom-Nikkor 12–24mm f/4G IF-ED (shown in Figure 1.2) allowed the camera to capture the equivalent of the 20–35mm lens.
Figure 1.2 The first DX lens, the AF-S DX Zoom-Nikkor 12–24mm f/4G IF-ED. The text on the lens tells you everything.
- VR—The VR designation means that the lens has the Nikon Vibration Reduction technology built into the lens. The VR technology tries to compensate for any lens shake when you are shooting at slower shutter speeds.
- VR II—Some of the newer lenses have the VR II designation, which is the second generation of the Nikon Vibration Reduction technology.
- ED—The Extra-low Dispersion glass produced by Nikon produces better looking images even with different light wavelengths. When this lens technology first came out, the lenses had a distinctive gold band and the ED label. This type of glass was a breakthrough for the longer focal lengths as it reduced the green-magenta color fringes that affected lenses at 300mm and longer.
- Micro-Nikkor—Lenses with the Micro-Nikkor designation are those designed for extreme close-up work. These would be called macro lenses by any other company.
- IF—The IF stands for Internal Focusing. These lenses do not change size when you are focusing.
- DC—The DC designation is for lenses that have the Defocus Control technology, which allows you to control how the out-of-focus background areas are rendered.
- N—The N designation means that the lens has a nanocrystal coating that improves the clarity of images. This technology was introduced in 2006 and was meant to replace the multilayer coating used previously.
Let’s look at a few of the most popular lenses in the Nikon lineup and decipher the code. One of my favorite lenses is the AF-S Nikkor 70–200mm f/2.8G ED VR II, which has a built-in Silent Wave Motor for autofocusing. It has a focal range of 70mm to 200mm and a maximum aperture of f/2.8 at all the focal lengths. This is a G-type lens, meaning it has no aperture ring. The lens also uses the ED glass and has the newest version of Vibration Reduction. The AF-S Nikkor DX 18–200mm f/3.5–5.6G ED VR II lens also has a built-in Silent Wave Motor for autofocusing and is specifically designed for cropped-sensor (or DX) cameras. The lens has a maximum aperture of f/3.5 at 18mm and f/5.6 at 200mm, and because it is a G-type lens, there is no aperture ring. The lens uses the ED glass and the latest Vibration Reduction technology.