Canon’s new 600mm and 800mm lenses

Started 3 months ago | Discussions thread
Jack Hogan Veteran Member • Posts: 7,493
DOE vs Phase Fresnel

bclaff wrote:

AiryDiscus wrote:


No, it doesn't simplify the lens design. My guess is that they use the front element as a stop, much as a telescope, so there is no stop at all (could be wrong). ...



(Example 3 is the 780mm lens)

Unfortunately I still haven't taught the Optical Bench to do diffractive elements

Are DOE elements the same as Nikon's Phase Fresnel, Bill? If so the bench would need a lot more detail on that front element.


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