In a report by CanonRumors, looks like a 1000mm replacement for the EF 800mm f/5.6L IS has just been patented with record showing an optical formula for an EF 1000mm f/5.6 IS DO. In earlier report, the prototype EF 600mm f/4 IS DO BR has already been outed and likely of a new DO lens could be inevitable, making a 1000mm a good replacement candidate. See full details of the patent below.
Patent Publication No. 2016-102852 (Google Translated)
- Published 2016.6.2
- Filing date 2014.11.27
- Zoom ratio 1.00
- Focal length 950.00
- F-number 5.80
- Angle of view 1.30
- Image height 21.64
- Overall length of the lens 485.94
- BF 0.40
- Canon patent
- Positive and negative Shibomake
- Diffractive optical element (first group)
- Inner focus (the second group)
Via CanonRumors