AF 180mm f/3.5 Di SP A/M FEC LD (IF) somewhat decoded...


From Bryan's review of the Tamron 28-75mm f/2.8 XR Di Lens, the breakdown is:



SP - Super Performance (Tamron's highest quality lens line)

AF - Autofocus

XR - Extra Refractive Glass (reduces lens size)

Di - Digitally Integrated Design (to reduce ghosting, flare, CA and peripheral light fall-off along with improved resolution)

LD - Low-Dispersion lens elements (to reduce chromatic aberration for sharper images)

Aspherical - contains aspherical elements (compensates for spherical
aberration and distortion, making for better performance with fewer
elements (and thus allowing for smaller, lighter lenses)

(IF) - Internal Focusing


[and not in Bryan's review]


FEC - Filter Effect Control function that enhances operational ease of Polarizing Filter use.


A/M - Autofocus & Manual focus (they may be referring to the clutch mechanism, or else a full time manual focus)