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| Canon EF 600mm f/4 DO BR lens |
Canon has a strong lead in
Diffractive Optics lens technology. They first introduced the EF 400mm f/4 DO IS back in 2001. I bought the lens in mid 2000s and made it my favorite
wildlife photography glass for handheld shots. It was not the sharpest lens in Canon's lineup but I was willing to trade that for the unmatched mobility and flexibility the lens offered.
In September 2014, Canon released the
EF 400mm f/4 DO IS II and the compromise was gone. The lens has 4 stops IS compensation, is tack sharp and still offers superb mobility. Canon demonstrated the
EF 600mm f/4 DO BR lens recently at the Canon Expo in September, 2015.
Last month, Canon filed for a
EF-M 600mm f/5.6 DO IS patent. Now, Egami has discovered another new Canon patent. This time it is for a EF-M 55-300mm f/4.5-5.6 DO IS lens. I am a bit puzzled how the DO version of these lenses would work in a mirrorless camera design that is already small, lightweight and consumer grade, unless Canon is planning to announce a
professional grade, full frame mirrorless camera some time in the future.
Patent Publication No. 2015-232674 (Google Translated)
- Published 2015.12.24
- Filing date 2014.6.11
- Zoom ratio 5.27
- Focal length 55.04 135.00 290.01
- F-number 4.60 5.18 6.30
- Angle of view 13.94 5.78 2.70
- Image height 13.66 13.66 13.66
- Overall length of the lens 136.00 175.46 192.00
- BF 35.50 35.50 35.50
