Canon EF-S 17-55 f/2 IS – Patent
EF-S 17-55 Replacement Coming?
A patent has been discovered showing the existence of an EF-S 17-55 f/2 IS lens.

Canon EF-S 17-55 f/2 IS
Canon EF-S 17-55 f/2 IS
Patent Publication No. 2010-14866
Published 2010/01/21
Filing Date: 2008/07/02
Example 1
Focal length f = 17.50 ~ 53.05mm
Brightness F = 2.0
Focus back 34.90 ~ 48.26mm
Example 2
Focal length f = 17.50 ~ 52.36mm
Brightness F = 1.8
Back Focus 34.15 ~ 45.06mm
General
Zoom is easy to increase the rate
Increase the amount of movement of the lens
But more aberration
Large diameter is easily
To compensate by increasing the number of lens aberration
But heavier
Patent literature
Placement of the lens to optimize the refractive index
Aspheric lenses
From Here: http://egami.blog.so-net.ne.jp/2010-02-08#more
CR’s Take
I’ve looked quickly, but I haven’t been able to find the actual patent anywhere. Can anyone else?
Thanks Justin




