New 400mm lens from Canon - rumour

[MatBin]

http://www.lens-rumors.com/new-patent-canon-400mm-f5-6-mirror-catadioptric-lens/

Now that could be interesting if it happens.
Years ago I had a 500 f8 mirror lens on a film camera (still have it somewhere), weighed next to nothing but wasnt an AF lens so the dark aperture made it difficult to manually focus as the centre spot blacked out very easily, be really interested to see if Canon can produce an AF mirror lens. They had very interesting bokeh, like ring doughnuts, could be a definite option as opposed to the DO 400 as they are light, if a bit delicate, easy to knock the mirror out of alignment, so I doubt it would be an L lens, so shouldnt be mega expensive.

Matt

 

[Graham W]

Can't see what's different to one of those 1970's mirror lenses to warrant a new patent.

 

[MatBin]

Can't see what's different to one of those 1970's mirror lenses to warrant a new patent.

Me neither, guess they feel it's AF and some sort of electric ND filter at the back that is self contained, would that make it a new enough to warrant a new patent?

 

[StewartR]

http://www.lens-rumors.com/new-patent-canon-400mm-f5-6-mirror-catadioptric-lens/

Now that could be interesting if it happens.

Something a bit funny with that article though. The existing Canon 400mm f/5.6 lens is 257mm long. That article says the one in the patent would be 247mm long. I'd really expect a catadioptric design to make the lens much shorter than that!

 

[MatBin]

Something a bit funny with that article though. The existing Canon 400mm f/5.6 lens is 257mm long. That article says the one in the patent would be 247mm long. I'd really expect a catadioptric design to make the lens much shorter than that!

True, maybe the "extras" make it a bit longer, I would imagine it will still be light though.
Tbh I doubt they'll make it, which is a shame as I would have imagined it a lot easier to make than the 400 DO.

 

[Brazo]

Sony produced a 500 F8 mirror lens (with af) back in 2006!

 

[StewartR]

Sony produced a 500 F8 mirror lens (with af) back in 2006!

Yes, but that's not the difficult bit. The issue up until now is that mirror lenses are stuck at one aperture; the Sony 500mm is an f/8 lens, but you can't stop it down to f/11 or f/16. This Canon patent suggests they have a way to overcome that. Sort of. Perhaps.

 

[Nod]

More light "permeable" elements?