<H1>Canon Patent : External Image Stabilization Unit</H1>

Egami, the Japanese photography blog has uncovered a Canon patent, showing an optional image stabilization unit that is external to a lens, without changing its focal length.

Patent Publication No. 2015-28555 (Google Translated)

•     Published 2015.2.12
•     Filing date 2013.7.30

Example 1a (master lens only)

•     Focal length 392.50
•     F-number 2.92
•     Half angle of 3.16
•     Image height 21.64
•     Overall length of the lens 379.64
•     BF 41.57
•     Effective diameter of the front lens 135.72mm
•     Lens configuration 8 groups nine

Example 1b (anti-vibration converter mounted state)

•     Focal length 392.50
•     F-number 2.92
•     Half angle of 3.16
•     Image height 21.64
•     Overall length of the lens 379.64
•     BF 41.56
•     Effective diameter of the front lens 135.72mm
•     Lens construction 12 groups 15 sheets

Canon Patent

•     3-group configuration of positive and negative positive
•     Inner focus (the second group)
•     The anti-vibration converter can be inserted on the object side of the third group