Reading the Lens
My lenses have various markings written on them. It’s about time I learned what those mean!
My first lens is the AF-S DX Zoom-NIKKOR 18-135mm f/3.5-5.6G IF-ED. On, the following lines are written “AF-S Nikkor 18-135mm 1:3–5.6G ED” and “DX SWM ED IF Aspherical ∞–0.45m/1.48ft ⊘67″.
My other lens is the AF-S DX VR Zoom-NIKKOR 55-200mm f/4-5.6G IF-ED. It has written on it “AF-S Nikkor 55-200mm 1:4–5.6G” and “DX SWM VR ED IF ∞–1.1m/3.61ft ⊘52″.
What do these mean?!
The easy part is the Nikkor part. A Nikkor is a camera lens by Nikon.
The mm number is the length of the lens. Since these are zoom lenses (thus the zoom in the lens names), they have ranges. 18-135mm for one lens, and 55-200mm for the other.
The 1: number is the aperture, which is listed as “1:3–5.6G ED” for the lens with a maximum aperture range of 3.5–5.6 (depending on zoom). The other lens lists “1:4–5.6G” with the len’s maximum aperture range being “4–5.6″. I don’t know what the “G” stands for. I don’t know why the former lens lists “ED” at the area, while both lenses list it elsewhere (so I’ll address it further down).
The AF-S refers to the len’s “AF-S (Silent Wave Motor)”, which is also what the SWM on the lens refers to.
The DX is mentioned on the lenses pages on Nikon’s site as being a “compatible format” with “DX”. My guess is that this means it’s compatible with the D-series of Nikon cameras, such as my D40.
The latter camera’s VR refers to the “vibration reduction” technology.
The IF means the lens has “internal focusing”, and the ED is “extra-low dispersion”, a glass element which “minimizes chromatic aberrations, contributing to superb contrast and resolution performance.”
Nikon’s page for the former of my two listed lenses lists “Aspherical (Elements): 0″, yet the lens has the word “Aspherical” right on it. Nonetheless, this probably refers to it having an aspherical lens, which is something I know nothing about.
The ⊘ part (with the line actually passing through the cicle on both sides) refers to the filter and lens attachment size. The ⊘67 is for a 67mm filter or lens attachment, and the ⊘52 is for 52mm filters and lens attachments.
The ∞–m/ft gives the minimum focus length, in meters and in feet. Maybe the ∞ is the maximum focus length? As for minimum, my former lens cannot focus on anything closer than 1.5 feet, and my latter lens cannot focus on anything closer than 3.6 feet.
I understand a lot of this now, but I sure didn’t “get” any of it before I had the Nikon D40 and used these lenses!