Canon EF 20mm f/2.8 USM - Review / Lab Test Report
Lens Reviews -
Canon EOS (APS-C)
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Special thanks to Mario Bobertz for providing this lens!
The Canon EF 20mm f/2.8 USM was released back in 1992 and it's one of the older
designs in the current lens lineup.
On APS-C DSLRs the field-of-view is
equivalent to 32mm so it looses its ultra-wide character towards a moderate
wide-angle lens here.
The optical construction is made of 11 elements in 9 groups without any
special glass. The aperture mechanism features 5 blades. With a min.
focus distance of 0.25m the max. object magnification is about 1:7.
The lens feature a floating system for close focus correction.
The EF 20mm f/2.8 USM has a size of 78x71mm and a weight of 405g so it is
roughly comparable to an average standard zoom here. The filter size is 72mm.
A lens hood is available as an option.
The lens has a decent though not stellar build quality based on good quality
plastics. The focus ring operates quite smooth but it was slightly wobbly in
the tested sample. The EF 20mm f/2.8 USM has a true IF design so its length
remains constant regardless of the focus setting. The front element
does not rotate so using a polarizer remains easily possible.
Despite its design age the lens features a very fast and near silent
ring-type USM drive incl. full-time manual focusing (FTM) in one-shot