Canon Patents

Patent: A zoom teleconverter, 1.0x-1.5x-2.0x

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Canon News has uncovered a patent showing a really cool idea from Canon, a zooming teleconverter. We’ve had teleconverters for a long time, but this is the first time I’ve seen or thought about a teleconverter that zooms.

This teleconverter can be switched between 1.0x-1.5x-2.0x.

This teleconverter doesn’t appear to have the same sort of design as the current teleconverters as the element doesn’t protrude into the lens it is attached to. Could this sort of TC be for folks with lenses such as the RF 70-200mm f/2.8L IS USM that cannot take the latest RF teleconverters?

We’ll have to wait and see on this one, as the patent isn’t too detailed. If Canon can make this compatible with lenses that the conventional teleconverters are not, this will sell.

H. Jones

Photojournalist
Aug 1, 2014
686
1,276
What an absolutely fascinating, innovative patent.

I was just having a conversation in another thread about how an external swing-in/swing-out teleconverter that works like the 200-400 isn't possible for all lenses, since when the optics swing out it changes the backfocus distance. This patent would solve that problem, since the optics don't simply just swing out of the optical path, but instead are always there to correct the backfocus change.

This is a great example of Canon looking into truly innovative and groundbreaking solutions in ways we haven't really thought of before.
 

Antono Refa

EOS R
Mar 26, 2014
1,292
425
My money is on this patent becoming a product.

The RF 70-200mm f/2.8 being incompatible with TC is ridiculous to the point I'm considering a switch to Nikon Z, rather than Canon RF.

I don't use the focal lengths over 200mm often enough to justify buying even a used EF 100-400mm, nor stuffing my bag with another big lens. The classic case for a TC. I don't see Canon releasing another RF 70-200mm f/2.8 any time soon either.

It might be wishful thinking on my side, but an innovative twofer, like the EF 8-15mm, seems like a reasonable plan.
 

tiggy@mac.com

R5
CR Pro
Jan 20, 2014
694
583
Thetford, VT
www.camnostic.com
Factors that will matter:
1) What is the t-stop loss with the adapter on. Without a swing-out mechanism, we're adding lots of glass between sensor and subject.
2) Image quality reduction rate, especially on the 1x setting, where there is no magnification benefit.

This could theoretically make buying EF glass into the future more attractive, unless the mechanism was included in new RF big whites.
 

Bdbtoys

R5
CR Pro
Jul 16, 2020
372
273
I'm looking forward to this becoming real. Would use on 70-200 & 100-500 in a heartbeat... and thinking out of the box a bit... would be interesting to see what this does on a fast prime.
 
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gatabo

I'm New Here
Feb 28, 2020
19
17
Factors that will matter:
1) What is the t-stop loss with the adapter on. Without a swing-out mechanism, we're adding lots of glass between sensor and subject.
2) Image quality reduction rate, especially on the 1x setting, where there is no magnification benefit.
assume the "loss" of quality is similar to other tele converters is OK, the loss at 1x is not that much important as you can always remove the TC for that focal length when needed.
 
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melgross

EOS RP
Nov 2, 2016
755
497
Interesting idea. When I first read the headline I missed that this was from Canon, and thought that these might be exactly what some cheap Chinese manufacturer would make, and so it couldn’t possibly be any good.

but then I realized it was from Canon, and it got more interesting. I doubt Canon would release junk. But this could simply be one of those patents that’s defensive in nature. So, a product category that they’ve investigated, and so feel others might investigate too. So getting a patent would prevent others from getting there, or at least slow them down.

the problem is, how good could a zoom tele converter really be, considering that unless it’s designed with just one lens in mind, it has to contend with light rays entering from different back elements of different sizes, at different distances, at different angles. It’s hard enough to make a general purpose teleconverter, and this must be considerably more difficult, and expensive.
 
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Mr Majestyk

EOS RP
Feb 20, 2016
410
265
Australia
Cool idea but will cost at least $2K IMO and weigh 400g. Too bad you'll never be able to use it on the 70-200's. I wonder if they'll make their new 135mm not take a TC too.
 

Antono Refa

EOS R
Mar 26, 2014
1,292
425
the problem is, how good could a zoom tele converter really be, considering that unless it’s designed with just one lens in mind, it has to contend with light rays entering from different back elements of different sizes, at different distances, at different angles. It’s hard enough to make a general purpose teleconverter, and this must be considerably more difficult, and expensive.

The same applies to any existing 1.4x and 2x TC. The raison d'etre for TCs is trading off image quality for size and price.

The EF 8-15mm's price settled on about twice the price of the EF 15mm. Reasonable, as it gives the functionality of two fisheye primes, if not more. Same with this extender. The RF 1.4x & 2x extenders cost $1,100 together, so Canon could charge as much for it.

I plan to buy an RF 70-200mm f/2.8. I don't want to buy a big 100-500mm for $2,700. As long as image quality doesn't take too big a hit, a small vari-extender for $1,350 sounds like a good deal.

And as Mark3794 wrote, this could be turn any prime into a zoom, e.g. it could turn an RF 35mm f/1.8 into a 35-70mm f/1.8-3.6. Sounds like a nice normal zoom.
 

snoke

EOS RP
Jul 20, 2017
306
47
And as Mark3794 wrote, this could be turn any prime into a zoom, e.g. it could turn an RF 35mm f/1.8 into a 35-70mm f/1.8-3.6. Sounds like a nice normal zoom.

No. 3 step zoom. Like Leica Tri-Elmar. 35/1.8 have 3 position. 35mm (1.0), 52.5mm (1.5), 70mm (2.0).
 

melgross

EOS RP
Nov 2, 2016
755
497
The same applies to any existing 1.4x and 2x TC. The raison d'etre for TCs is trading off image quality for size and price.

The EF 8-15mm's price settled on about twice the price of the EF 15mm. Reasonable, as it gives the functionality of two fisheye primes, if not more. Same with this extender. The RF 1.4x & 2x extenders cost $1,100 together, so Canon could charge as much for it.

I plan to buy an RF 70-200mm f/2.8. I don't want to buy a big 100-500mm for $2,700. As long as image quality doesn't take too big a hit, a small vari-extender for $1,350 sounds like a good deal.

And as Mark3794 wrote, this could be turn any prime into a zoom, e.g. it could turn an RF 35mm f/1.8 into a 35-70mm f/1.8-3.6. Sounds like a nice normal zoom.
Not exactly. Those can be optimized to their magnification. A zoom can’t. The IQ will always be lower.
 

degos

EOS RP
Mar 20, 2015
383
321
This is a great example of Canon looking into truly innovative and groundbreaking solutions in ways we haven't really thought of before.

s-l300.jpg
 
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