Canon RF 800mm f/5.6L IS USM and Canon RF 1200mm f/8L IS USM coming soon?
- Thread starter Richard CR
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Link? Can a catadioptric lens even have image stabilization? I'm not aware of any examples. Canon patented a 400/5.6 catadioptric lens a few years ago, but it didn't have IS.
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I don't think so. I think most IS systems don't move the front element, and in a catadioptic system if the rear spherical mirror doesn't stay properly aligned with the front convex mirror (and by relationship with the front glass element) then major distortions happen. I suppose they could have a system that moves it all together. They know more about optics than we do afterall, but we haven't seen an example yet.
Brian
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I'd be absolutely amazed if it was a catadioptric lens - the "donut" look has never been popular and I can't see many people spending thousands on such an optic. Perhaps "Inz", whose post has for some reason been deleted, meant to say "fresnel" instead of "catadioptric"?
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A patent doesn't prove anything, but it looks like it is possible it will be:
Patent: Is Canon planning to release catadioptric (mirror) super telephoto lenses?
Keith over at Northlight uncovered a USPTO patent showing various optical designs for catadioptric lenses, better known as mirror lenses. The advantages to mirr
www.canonrumors.com
And it actually looks like they have IS:
Canon RF & EF Lenses - rumours & news
Rumours and news about lenses. Canon EF and RF lenses. Third party lenses, design information and patents. Lens testing and usage tips
www.northlight-images.co.uk
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Genuine question: Would you still find it tempting, if it turned out to be a catadioptric lens, with accompanying donut bokeh?
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An excellent catadioptric lens isn't necessarily small and lightweight. Who remembers the Carl Zeiss Mirotars 4,5/500 and 5,6/1000?
And they were definitely not inexpensive. I'd be surprised if Canon were ready to compromise on quality.
As a non-L lens, it would cost far less , of course. But who could handle such a lens, if not an experienced photographer, with the right (heavy) tripod?
And they were definitely not inexpensive. I'd be surprised if Canon were ready to compromise on quality.
As a non-L lens, it would cost far less , of course. But who could handle such a lens, if not an experienced photographer, with the right (heavy) tripod?
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I also doubt canon would do a CAT 1200mm f8, donut backgrounds in bird photos are just no good. A close facsimile would be the Pentax 1200mm f8. 684mm long and nearly 8580g in weight. If we assume that as base and Canon does incorporate DO element in it length would likely shrink to around 500mm and weight 5500g, which would still be big, but be manageable for a 1200mm. It certainly also would not command the $100k+ pricetag the f5.6 does.
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We actually had this discussion internally. Cats are hard, they are also hard to keep their alignment perfect as well. Especially one with a 150mm f1200 cat optic. They also have a bear of a time as far as temperature control. Also if it was a Cat - I REALLY doubt it would be an L lens, as I'm not even sure you could fully weather seal a Cat.
As far as AF and IS, sure - because you have to have field correctors, and focusing elements on the back end of the Cat, and there you'd have your floating IS unit and AF motors, etc. Just like with a telescope you have your eyepiece coming out of the back of the Cat.
I really doubt it's a cat, I suspect it will be DO and be around the same size as the 800mm .. if you think about it, the 800mm F5.6 and the 1200mm F.8 will have roughly the same size as the front element. With DO, it would be smaller and around the same length as the 800mm.
That's my theory.
As far as AF and IS, sure - because you have to have field correctors, and focusing elements on the back end of the Cat, and there you'd have your floating IS unit and AF motors, etc. Just like with a telescope you have your eyepiece coming out of the back of the Cat.
I really doubt it's a cat, I suspect it will be DO and be around the same size as the 800mm .. if you think about it, the 800mm F5.6 and the 1200mm F.8 will have roughly the same size as the front element. With DO, it would be smaller and around the same length as the 800mm.
That's my theory.
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There does appear from the last couple of posts that there is excitement about 800/6.3. However, 800mm is too specialised for me, in terms of both field of view and probably minimum focal distance. I'd prefer a 500/4, which has a similar size front element, with the versatility of 700mm and 1000mm with TCs. It will be interesting to see how well the 800/6.3 sells.
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