|Electronic Focus lenses.
|Electronic Focus lenses that
have been designed to only be used on EOS Digital SLR cameras.
|Ultra sonic motor. There are
two types found in Canon EF lenses, Ring-type USM found in large-aperture
and super telephoto lenses and the Micro USM used in more compact lenses.
|Defraction Optical. Lenses
contain multi DO elements combined with a convext lens to almost completely
cancel out chromatic aberration. This allows the lense to be significantly
shorter and lighter to a typical refractive lens. An example is the EF 400mm
f/4 DO IS USM is 27% smaller and 31% lighter than a conventional 400mm f/4
|Image Stabalizer - detects and
corrects slight camera shake but also allows steady shooting up to 4 stops
lower than conventional lenses. Some lenses have Is mode 2 which detects if
movement in a certain direction occurs for longer than a preset time and
then it switches off the IS in that direction.
|L Series lenses are all
Electronic Focus and they are identified in the Canon range with their white
lens barrel. Designed with the professional in mind they have been created
to withstand the rough handling and extreme conditions some pro
photographers find themselves in as well as being weather proof including
water resistant. See
link for information
on the L-Lens
|Canons name for a
|Ultra-low dispersion glass
used in the lens elements.
|A lens coating which has been
optimized and shaped to suppress flare and ghosting. Also believed to help
achieve true colour balance and increase contrast.
|Allows the ability to focus at
closer distances for smaller items such as insects and small flowers.
Dedicated macro lenses have the rations 1:2.5, 1:2.8, 1:3.5
|Manual focus macro lens 1:2
1-5x. Achieves a higher magnification greater than 1x suitable for small
|Tilt and Shift mechanism ideal
for architectural photography.