<H1>Canon Patent - DO Lens for APS-C Sensor</H1>

Canon EF 400mm f/4 DO IS II lens

My readers know I am a fan of Canon's Diffractive Optics technology. The current EF 400mm f/4 DO IS II is my favorite Super Telephoto lens when I want to travel light. Canon has been working to perfect the DO technology since the first EF 400mm f/4 DO IS lens came out in 2001. The EF 600mm f/4 DO BR lens was showcased in last year's Canon EXPO at New York City.

Now, a new Canon DO patent has been uncovered for the APS-C sensor. The new design has a focal length of 50-300mm f/4.5-6 with STM. As of now, there is no built-in IS but this is of course a work in progress and if Canon decides to release this DO lens for the APS-C market, I am certain it will come with Image Stabilization.

Patent Publication No. 2016-57444

• Published 2016.4.21
• Filing date 2014.9.9

Example 1

• Zoom ratio 5.59
• Focal length 51.77 135.00 289.53
• F-number 4.65 5.05 5.85
• Half angle of view (degrees) 14.78 5.78 2.70
• Image height 13.66 13.66 13.66
• The total lens length 126.05 169.37 184.15
• BF 35.50 35.50 35.50

Example 2

• Zoom ratio 5.90
• Focal length 49.13 135.00 290.00
• F-number 4.65 4.95 5.85
• Half angle of view (degrees) 15.54 5.78 2.70
• Image height 13.66 13.66 13.66
• The total lens length 108.00 152.12 168.00
• BF 15.69 15.69 15.69