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



## Canon Rumors Guy (Dec 10, 2020)

> 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...



Continue reading...


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## H. Jones (Dec 10, 2020)

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.


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## Antono Refa (Dec 10, 2020)

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.


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## [email protected] (Dec 10, 2020)

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.


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## edoorn (Dec 10, 2020)

70-200? What about a great option for the new RF big whites? I'd glue this thing on a 400 2.8 in a heartbeat!


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## Mark3794 (Dec 10, 2020)

Almost a prime to zoom converter


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## BeenThere (Dec 10, 2020)

I have a feeling that image degradation of this option will not be my cup of tea. All-in-ones usually have compromises in optics (e.g., zooms vs primes).


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## Bdbtoys (Dec 10, 2020)

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 (Dec 10, 2020)

[email protected] said:


> 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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## StoicalEtcher (Dec 10, 2020)

I may be wrong, but was't there some talk a few months ago about an "innovative" t/c? Might this be it?


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## melgross (Dec 10, 2020)

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 (Dec 10, 2020)

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.


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## ColinJR (Dec 11, 2020)

Please work with TS-E lenses! Please work with TS-E lenses! Please work with TS-E lenses! Please work with TS-E lenses!


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## Antono Refa (Dec 11, 2020)

melgross said:


> 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.


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## snoke (Dec 11, 2020)

Antono Refa said:


> 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).


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## sanj (Dec 11, 2020)

Brilliant idea


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## sanj (Dec 11, 2020)

Mr Majestyk said:


> 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.


Too many assumptions here. Just too many.


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## BeenThere (Dec 11, 2020)

A better idea is a 1.4x TC / EF-RF converter that fits into same or smaller space as the current EF-RF converter. Are you listening Canon?


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## melgross (Dec 11, 2020)

Antono Refa said:


> 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.
> 
> ...


Not exactly. Those can be optimized to their magnification. A zoom can’t. The IQ will always be lower.


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## degos (Dec 11, 2020)

H. Jones said:


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


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## styoda (Dec 11, 2020)

Is that 4 elements and 2 groups ? isn't that insane if it is, not a lot of glass compared to the current converters ?


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## AlanF (Dec 11, 2020)

I regularly switch from native to 1.4 to 2xTC during the course of shooting in a day. This TC would be convenient but with the drawback that at 1x it would degrade the IQ of the bare lens without any advantage at the native focal length because of the extra elements. Still, I suppose you would put it on only when you want a longer focal length but have the opportunity to zoom out quickly.


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## analoggrotto (Dec 12, 2020)

StoicalEtcher said:


> I may be wrong, but was't there some talk a few months ago about an "innovative" t/c? Might this be it?



That might have been the C70's speed boosting converter. 

But we can always use another innovative adapter. Canon is going to show the game up with optics yet again.


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## analoggrotto (Dec 12, 2020)

Sony never innovated with lenses outright. They improved function, speed and delivered unquestionably good quality (consistency between copies may have lacked) but never accomplished anything new or pushed the boundaries of optical design. Canon is doing this right out of the gate (with some costs), so many optical tricks to bring versatility and use-cases to the new bodies. Not just mirrorless for mirrorless sake. I'd love to know when canon actually pulled the trigger on R&D for the RF platform or if they just had it in the background for a long time, tweaking, patenting and refining.


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## Antono Refa (Dec 12, 2020)

melgross said:


> Not exactly. Those can be optimized to their magnification. A zoom can’t. The IQ will always be lower.



Question is how much IQ is traded for size, price, and convenience. Personally, I find the possibility of having a TC for the RF 70-200mm is good news.


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## chasingrealness (Dec 12, 2020)

This is [only] brilliant [if they can pull it off without degrading IQ at 1x]!

Legend: Read without brackets for my first impression and then again with text in brackets included for the thought that immediately followed.


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## Bdbtoys (Dec 12, 2020)

chasingrealness said:


> This is [only] brilliant [if they can pull it off without degrading IQ at 1x]!
> 
> Legend: Read without brackets for my first impression and then again with text in brackets included for the thought that immediately followed.



I don't believe 1x will be free (absolutely no loss), however if there is no appreciable IQ loss I think most will find that acceptable... as the use case from flipping 1x to 1.5x to 2x and back w/o a lens change is worth it.


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## melgross (Dec 12, 2020)

styoda said:


> Is that 4 elements and 2 groups ? isn't that insane if it is, not a lot of glass compared to the current converters ?


Yes. And that’s something that bothered me. This seems to be just too simple. I would have expected an 8 element design, if not more.


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## melgross (Dec 12, 2020)

Antono Refa said:


> Question is how much IQ is traded for size, price, and convenience. Personally, I find the possibility of having a TC for the RF 70-200mm is good news.


Sure, if the IQ was good. But even Canon;s regular converters drop IQ by differing amounts depending on the lens and on the length of the lens. A zoom converter will be worse. Sometimes it’s just better to crop.


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## Antono Refa (Dec 13, 2020)

styoda said:


> Is that 4 elements and 2 groups ? isn't that insane if it is, not a lot of glass compared to the current converters ?



My impression from the images and the auto translation to English is the patent is about the mechanics of the adapter, not the optics. 

E.g. the "problem to be solved" is "to provide an adapter device advantageous for moving an optical element in a direction of an optical axis, for example", and "patent document 1 has a built-in ND filter, discloses an adapter device having a function of adjusting the amount of light". The text mentions possibilities of having different mounts at each side, and the connected lens' power of coverage differing from the camera's sensor size.

The patent might be generalized to cover more ground (a vari extender that's also a mount adapter), but I still get the impression the optics & their functionality is an example of what the patented mechanics could be used for.


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## melgross (Dec 13, 2020)

analoggrotto said:


> Sony never innovated with lenses outright. They improved function, speed and delivered unquestionably good quality (consistency between copies may have lacked) but never accomplished anything new or pushed the boundaries of optical design. Canon is doing this right out of the gate (with some costs), so many optical tricks to bring versatility and use-cases to the new bodies. Not just mirrorless for mirrorless sake. I'd love to know when canon actually pulled the trigger on R&D for the RF platform or if they just had it in the background for a long time, tweaking, patenting and refining.


When Canon went to the EOS mount in the mid 1980’s, it took them three years to decide on the feature set and the exact physical design. I imagine this took a similar path to fruition.


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## analoggrotto (Dec 14, 2020)

melgross said:


> When Canon went to the EOS mount in the mid 1980’s, it took them three years to decide on the feature set and the exact physical design. I imagine this took a similar path to fruition.


It's almost as if the registration distance, mount and then lenses were well developed while the sensor and DPAF tech caught up. Canon's full frame mirrorless decision may have pre-dated Nikon's.


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## melgross (Dec 14, 2020)

analoggrotto said:


> It's almost as if the registration distance, mount and then lenses were well developed while the sensor and DPAF tech caught up. Canon's full frame mirrorless decision may have pre-dated Nikon's.


It’s possible. I don’t think any of this. Alters though. What matters is how good it is once it gets here, and it’s all pretty good indeed.


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## analoggrotto (Dec 15, 2020)

melgross said:


> It’s possible. I don’t think any of this. Alters though. What matters is how good it is once it gets here, and it’s all pretty good indeed.


Agreed. It is good, so good that I bought 2 RF lenses without an R body in hand. It was worth it.


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## melgross (Dec 15, 2020)

analoggrotto said:


> Agreed. It is good, so good that I bought 2 RF lenses without an R body in hand. It was worth it.


That’s funny, because I was thinking the same thing. But I had a detached retina in my left eye, and I’m left eyed. I’m still working on that eye, which has problems. So I haven’t decided to lay maybe $10,000 down on something until I’m sure it won’t be a problem. Using my right eye is so distracting, it’s impossible to do it without thinking.


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## Dpickup (Dec 16, 2020)

Id buy one in a heartbeat - if i can get full zoom range back on my 100-500 would be worth it for me.
using on other lenses would be a bonus


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## analoggrotto (Dec 17, 2020)

melgross said:


> That’s funny, because I was thinking the same thing. But I had a detached retina in my left eye, and I’m left eyed. I’m still working on that eye, which has problems. So I haven’t decided to lay maybe $10,000 down on something until I’m sure it won’t be a problem. Using my right eye is so distracting, it’s impossible to do it without thinking.


My coworker had this happen to his son from an unseen tackle. Sorry for your ailing. I am down 4 and 5 diopeters, wearing contacts finally put my eye into the viewfinder and I started to take pictures at last. I am left eye dominant (yet right handed) so I'd prefer to use my left eye for some compositions but then my nose starts messing with the touch screen focus ... oii.


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## Dom_33 (Aug 31, 2021)

Hi,
Any news about this zoom / converter ?
Definitely, that should be a real benefit to RF zoom like RF 100-500 (without mounting problems with actual RF extenders ...).
Dom


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## FrenchFry (Aug 31, 2021)

I would love to see this TC announced!


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