Lens Alphabet Soup

Decoding the information on your camera lens

I’m looking at one of my lenses and there’s an absolute ton of terminology here! Engraved on the front of the lens barrel, I see:

M.Zuiko Digital 40-150mm 1:2.8 Ø72

On the bottom of the lens barrel, it reads: OM System 40-150mm 1:2.8 PRO

Some of the information is fairly straightforward, and found on almost all lenses:

• 40-150mm | Focal length range (zoom lenses)

• 1:2.8 | Maximum lens aperture, in this case, f/2.8

• Ø72 | The front filter thread diameter, in this case, 72mm

The bottom of the lens is more of a brand description, and includes the term “PRO” simply to designate the build and optical quality of the lens. You’ll see a lot of different designations between each manufacturer as they try to discriminate between lower-end and pro-quality lenses. For example, Nikon uses the “S” designation for its top-end Z-mount glass, while Sony has “G” (gold) and then an even higher “GM” (gold master) designation in its lens lineup. Similarly, Canon uses the “L” designation for it’s top-end glass, and Fujifilm uses a red badge on their best lenses.

M.Zuiko is OM System’s brand name for their in-house lenses. Similar to how Nikon refers to their lenses as “Nikkor,” or Fujifilm’s “Fujinon” lenses.

Turning the lens over reveals even MORE information: