Possible Duplicate:
What do all those cryptic number and letter codes in a lens name mean?
Canon EF 50mm f/1.8 II
What does EF, II mean?
Sigma 10mm/F2.8 EX DC Fisheye HSM compatibil Canon
What do EX,DC,HSM mean?
Nikon AF-S DX NIKKOR 55-200mm f/4-5.6G ED VR
What do AF-s, Ed, Vr mean
Sigma 50-200mm/F4-5.6 DC OS HSM Canon what does DC, OS, HSM mean
Can you pease explain any other abbreviations? I really couldn't find a good resource
EF = Elecronic Focus, this is the name of Canon's autofocus mount. "II" means the second version of the lens.
EF-S = Canon's designation for EF "short back focus" lenses designed to satisfy the APS-C crop factor
EX = Sigma marketing term, denotes a higher build level. DC means the image circle is only covering APS-C ("crop").
HSM = Sigma's designation ultrasonic motor.
AF-S = Nikon's designation that the lens has the focusing mechanism in the lens, as opposed to being driven by the camera body. The mechanism is usually ultrasonic.
ED = Nikon's designation for glass with high extra-low dispersion.
VR = Nikon's designation for image stabilization in the lens ("Vibration reduction").
OS = Sigma's designation for image stabilization.
L = Denotes Canon's high-end lenses ("luxury")
IS = Canon's designation for image stabilisation
USM = Canon's designation for ultra-sonic motor motor
For Nikon Lenses here's complete list, straight from the official web site.
The "problem" with lens acronyms is that each company has its own and you usually end up with different letters for the same features. For more info read the answers to this question.
