This is a fun little optical formula. Does your EOS M need a super telephoto solution that doesn’t weigh too much? Then a 600mm f/5.6 DO IS could be just the ticket.
Patent Publication No. 2015-215437
- Published 2015.12.3
- Filing date 2014.5.9
- Focal length 585.00
- F-number 5.74
- Half angle (in degrees) 1.34
- Image height 13.66
- Overall length of the lens 299.25
This is probably Canon covering all their 600mm DO options.