Glossary of Terms (3)

Canon aberration STM describes new focusing motor type and stands for Stepper Motor. First EF lens to incorporate this type of motor was Canon EF 40mm f2.8 STM. Main purpose for this type of motor was to utilize more silent and smooth focusing and object tracking during video recording with new Canon camera releases like EOS 650D, EOS700D and mirrorless EOS-M and their new hybrid AF sensor. EF STM lenses will work with older types of EOS cameras but it is still questionable how will they preform regarding speed and accuracy of AF system not using hybrid AF sensor. ( this is a nice topic for Article About Lenses section)  EOS-M also introduced  new EF-M lens mount  which will be utilized only for Canon's  mirrorless cameras.  

SP stands for Tamron´s Super Performance and describes Tamron's high performance lenses featuring high design specifications. It is always placed as firt two letters in lens name eg. (SP 70-200mm F/2.8 Di VC USD)

Special portrait lens that allows for taking softened photos without additional filters thanks to its special optical design.