Canon Patent Application: Miniaturization of built-in teleconverter

[Richard CN]

In this Japan Patent Application, JP 2023-118490, Canon is investigating creating smaller built in teleconverters for use in lenses that we would normally not expect to see a teleconverter installed in. The idea of this patent application is to make the mechanism and the sliding out of the optical elements that make up the teleconverter

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[Emyr Evans]

Surely a 50mm F1.2 would end up as a 70mm F2.0 with the tele-converter? Assuming a traditional 1.4x magnification.

 

[domo_p1000]

Surely a 50mm F1.2 would end up as a 70mm F2.0 with the tele-converter? Assuming a traditional 1.4x magnification.

I thought just that, but there would be nothing to stop Canon from using 'any' strength of magnification for a built-in solution, so while it is not traditional, a 1,7x magnification would produce those two familiar prime lenses.

It does have the potential to open up a few useful pairs of lenses, although I can't help but think that the wider the lens, the more demanding the optical formular for a teleconverter.
35mm | 50mm (1.4x)
24mm | 50mm (2.0x -ish!)
35mm | 70mm (2.0x)

 

[EOS 4 Life]

The lens is pretty small over all.
Obviously, they used a wide angle lens to demonstrate how small it can be but this would be great for telephoto lenses.

 

[Maximilian]

Sounds interesting.
If the size is as small as mentioned, I hope that Canon can keep the IQ at the level of "normal" TCs.

 

[Maximilian]

The lens is pretty small over all.
Obviously, they used a wide angle lens to demonstrate how small it can be but this would be great for telephoto lenses.
View attachment 211031

Thanks for sharing that drawing.
The lens looks quite bulky. If such a design were the practical implementation, I don't know if it would feel good in the hand.

 

[LSXPhotog]

I’m watching this product with a lot of interest. As it stands right now, it’s just far too large to be a practical option right now. I have concerns about how this will interfere with my knuckles when it’s this close to the grip. I already have some minor issues with the RF 85mm f/1.2 and this appears to be noticeably worse.

 

[EOS 4 Life]

As it stands right now, it’s just far too large to be a practical option right now.

How so?
It is smaller than the ones Canon and Nikon currently use.

 

[Docofthewild]

How so?
It is smaller than the ones Canon and Nikon currently use.

Is it though? I can’t speak to the scale of the camera in the patent drawing but assume is is reasonably close. The EF 200-400 has plenty of room between the lens and grip yet, in the patent drawings, this new converter appears to be overlapping it. Plus the 200-400 has a drop in filter as well.



I can’t read the patent so I don’t know how much more info there is in there. In the images, there appears to be at least 3 positions; the 2 extra groups completely out of the way, the 2 groups in position close to the stationary group and the 2 groups in position and farther back from the stationary group. Is this meant to represent the process of going from 1x to 1.4x or have the come up with a way to have a 1x and then engage a “zoom” from 1.4-2x? The 2x has always had additional lenses/groups compared to the 1.4x so just using distance between the groups would be a new approach for a teleconverter. Very cool if so, theoretical 300 f2.8 would flip to a 420-600 f4-5.6.

 

[EverydayPhotographer]

Sounds interesting.
If the size is as small as mentioned, I hope that Canon can keep the IQ at the level of "normal" TCs.

There's a good potential that it could be even better, being engineered for the specific lens rather than being a "one size fits all" solution for all lenses and types.

 

[GMCPhotographics]

The animation seems to suggest a 3 way optic. So, a native with out extended, a 1.4x and maybe a 2x?

 

[FabFR]

The animation seems to suggest a 3 way optic. So, a native with out extended, a 1.4x and maybe a 2x?

I think the optical formula of the converter is too long to be integrated as a whole, so they split the optical block in two, in order to allow these two parts to park in a smaller place.

 

[EricN]

I think the optical formula of the converter is too long to be integrated as a whole, so they split the optical block in two, in order to allow these two parts to park in a smaller place.

That's what it looks like to me.

 

[Czardoom]

Is it though? I can’t speak to the scale of the camera in the patent drawing but assume is is reasonably close. The EF 200-400 has plenty of room between the lens and grip yet, in the patent drawings, this new converter appears to be overlapping it. Plus the 200-400 has a drop in filter as well.
View attachment 211072
View attachment 211073

I can’t read the patent so I don’t know how much more info there is in there. In the images, there appears to be at least 3 positions; the 2 extra groups completely out of the way, the 2 groups in position close to the stationary group and the 2 groups in position and farther back from the stationary group. Is this meant to represent the process of going from 1x to 1.4x or have the come up with a way to have a 1x and then engage a “zoom” from 1.4-2x? The 2x has always had additional lenses/groups compared to the 1.4x so just using distance between the groups would be a new approach for a teleconverter. Very cool if so, theoretical 300 f2.8 would flip to a 420-600 f4-5.6.

Generally speaking, the lens and camera depicted in a patent for something other than a lens or camera, is generic, or purely a "placeholder". In other words, the only accurately drawn piece of equipment in a TC patent is the TC, at least from what I have seen in the past.

 

[EOS 4 Life]

Is it though? I can’t speak to the scale of the camera in the patent drawing but assume is is reasonably close

Well, it does expand but you can see in the animation that Richard made how small it gets.
I am not sure that it is any smaller expanded.
External expansion would irk some people but it will still be more convenient than adding an external TC.

 

[LSXPhotog]

How so?
It is smaller than the ones Canon and Nikon currently use.

Hmmm, you must be look at something completely different than me because the one shown in these design sketches is twice the circumference and significantly longer than the existing RF 1.4X and 2.0X....so it's not in any dimension smaller than the current ones.

 

[LSXPhotog]

How so?
It is smaller than the ones Canon and Nikon currently use.

This thing is absolutely massive and in no way smaller than the current teleconverters.

 

[EricN]

@Czardoom was pointing out that in documents like this, only the lens will be drawn accurately, i.e., the camera's size, in the drawing, is arbitrary. It makes sense to me to draw the TC bigger and the camera smaller in order to show the parts of the TC, while the camera is not very important to the drawing.

 

[EOS 4 Life]

This thing is absolutely massive and in no way smaller than the current teleconverters.

It is smaller than the current switchable built-in teleconverters.
That is the entire point of the patent.
Most of the illustrations are of a lens with a built-in teleconverter.
We are not just seeing the size of the teleconverter.
We are seeing the enter size of a lens with a built-in switchable teleconverter.
It is built into a wide-angle lens.
That is not very helpful in determining the size since it would be in a super telephoto lens in reality.
It is a patent, not an advertisement so it is not designed to be helpful.

 

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I always thought it was a lost opportunity not to have a TC EF/RF adapter. I suspect it would have had to have been a very weird shape to allow elements to get out of the optical chain.

I find myself putting on and taking off TCs with more frequency than I'd like, and almost always in muddy conditions.