New type of teleconverter coming from Canon alongside a Supertelephoto zoom

[markschneider]

Like PinholeR5 said it's a great concept. I had to laugh when the article said it won't be cheap. I think they should throw in a camera with the purchase of an "L" lens. LOL. $10k for a lens, what's another $2k for a teleconverter. Still, to have that extra reach for shooting at Yellowstone would be worth it.

 

[Loswr]

Question: is part of the reason of having the protrusion on the current extenders mechanical stability and / or weather-proofing?

I'd say no. The protrusion is within the barrel, so weather sealing has nothing to do with it. Likewise, the protrusion does not touch the lens being paired with, so no affect on mechanical stability. One effect is that it makes the lens + TC combination a few millimeters shorter than it would be if the outer barrel was extended to be flush with the optics.



The main reason, from what I can tell, is to restrict extended compatibility to only those lenses Canon wants to be compatible. For EF, ‘official’ compatibility was restricted to L lenses 135mm or longer. When the 70-300L came out, it was listed as incompatible with the extenders, but that changed ‘officially’ with the 1D X firmware update that enabled f/8 AF, when the 1.4x was listed as compatible (even though it was not reported to the body, since the lens lacks the three extra pinouts). However, the EF 70-300L was compatible in the same way that the RF 100-500 is compatible, i.e. only at the longer end of the zoom range.

In any case I'd be in the market for this for sure. But first I need to see some tests about the impact on image quality at all settings, especially 1x. If it works well it'd be great not having to choose among nothing / 1.4x / 2x

Me, too. If such a TC is announced, I'll preorder it. But I am concerned about IQ degradation at 1x. Still, I would be willing to trade a slight IQ at 1x hit for the convenience of 1x, 1.4x, 2x switchable.

I'm not yet convinced it will be 1x / 1.4x / 2x. It may be just two position, without the 1x option. Time will tell.

 

[Fischer]

Would be super interesting if it could work with the 135mm f/1.8!

 

[sanj]

I'd say no. The protrusion is within the barrel, so weather sealing has nothing to do with it. Likewise, the protrusion does not touch the lens being paired with, so no affect on mechanical stability. One effect is that it makes the lens + TC combination a few millimeters shorter than it would be if the outer barrel was extended to be flush with the optics.

View attachment 209280

The main reason, from what I can tell, is to restrict extended compatibility to only those lenses Canon wants to be compatible. For EF, ‘official’ compatibility was restricted to L lenses 135mm or longer. When the 70-300L came out, it was listed as incompatible with the extenders, but that changed ‘officially’ with the 1D X firmware update that enabled f/8 AF, when the 1.4x was listed as compatible (even though it was not reported to the body, since the lens lacks the three extra pinouts). However, the EF 70-300L was compatible in the same way that the RF 100-500 is compatible, i.e. only at the longer end of the zoom range.


Me, too. If such a TC is announced, I'll preorder it. But I am concerned about IQ degradation at 1x. Still, I would be willing to trade a slight IQ at 1x hit for the convenience of 1x, 1.4x, 2x switchable.

I'm not yet convinced it will be 1x / 1.4x / 2x. It may be just two position, without the 1x option. Time will tell.

Maybe the 1x means no effect. In other words, keep the TC mounted all the time! Keep it on 1x when TC is not needed. If this is true, it will be awesome for me. Keep in on the camera and no dust goes in. So off, 1.4 and then 2x. I like.

 

[Loswr]

Maybe the 1x means no effect. In other words, keep the TC mounted all the time! Keep it on 1x when TC is not needed. If this is true, it will be awesome for me. Keep in on the camera and no dust goes in. So off, 1.4 and then 2x. I like.

Yes, that's what 1x means. But that requires optics, because otherwise it would be the same as an extension tube – higher magnification, but loss of the ability to focus on distant subjects. The question is, if 1x is available in this TC how much to the required optics affect the IQ compared to the bare lens?

 

[Del Paso]

Wouldn´t it be advantegeous for Canon to make it compatible with other RF-glasses as well ? At least I hope it will. Could be used with RF 70-200mm:s and hopefully also with RF 100-500mm for the whole focal length.

Certainly!
But the risk would be to compromise optical quality in order get a more universal use.
Those who buy the big whites are, in my opinion, very demanding customers, unwilling to sacrifice TC's quality after having spent $10000 + on a lens. This is why specific TC's are being developed by Canon!

 

[Del Paso]

Yes, that's what 1x means. But that requires optics, because otherwise it would be the same as an extension tube – higher magnification, but loss of the ability to focus on distant subjects. The question is, if 1x is available in this TC how much to the required optics affect the IQ compared to the bare lens?

Right!
The question is not "if", but "how much" of the lens' IQ will be affected.

 

[Tony5787]

Take my damn money! I can’t imagine this not working with the other RF supertele’s like the 400 f/2.8 and 600 f/4. Really looking forward to pairing this with my new 400 RF, having a setup that can go from 400 f/2.8 to 560 f/4 to 800 f/5.6 at the flip of a switch is a dream come true. I doubt IQ will be as good as the existing TC’s but in scenarios where weather is harsh or I know I’ll need the versatility this will be a no-brainer.

 

[roby17269]

I'd say no. The protrusion is within the barrel, so weather sealing has nothing to do with it. Likewise, the protrusion does not touch the lens being paired with, so no affect on mechanical stability. One effect is that it makes the lens + TC combination a few millimeters shorter than it would be if the outer barrel was extended to be flush with the optics.

View attachment 209280

The main reason, from what I can tell, is to restrict extended compatibility to only those lenses Canon wants to be compatible. For EF, ‘official’ compatibility was restricted to L lenses 135mm or longer. When the 70-300L came out, it was listed as incompatible with the extenders, but that changed ‘officially’ with the 1D X firmware update that enabled f/8 AF, when the 1.4x was listed as compatible (even though it was not reported to the body, since the lens lacks the three extra pinouts). However, the EF 70-300L was compatible in the same way that the RF 100-500 is compatible, i.e. only at the longer end of the zoom range.

did not know about that limitation for the EF 70-300L... never had one. What you say makes sense although personally I'd much prefer Canon giving us the freedom to use extenders with most lenses and let us deal with lack of AF like the "adult" photographers

Me, too. If such a TC is announced, I'll preorder it. But I am concerned about IQ degradation at 1x. Still, I would be willing to trade a slight IQ at 1x hit for the convenience of 1x, 1.4x, 2x switchable.

Agree that there will be an impact at 1x, it's unavoidable. Question being how much? Also the 2x has a significant impact already, if the new adapter will be worse than that at 2x, that will be another minus. If it will turn out to be acceptable at 1.4x only I may change my buying intention.

I'm not yet convinced it will be 1x / 1.4x / 2x. It may be just two position, without the 1x option. Time will tell.

One can dream it would make for a great "Canon can be innovative" talking point

 

[AlanF]

Yes, that's what 1x means. But that requires optics, because otherwise it would be the same as an extension tube – higher magnification, but loss of the ability to focus on distant subjects. The question is, if 1x is available in this TC how much to the required optics affect the IQ compared to the bare lens?

There has to be a hit, as you say, the question is by how much. The rule of thumb in the past was that a 1.4x lost 10% and a 2x 20% of the MTF50. However, some of that is due to the increased diffraction with increased f-number so maybe the hit will be only a couple of percent.

 

[miketcool]

For me, first key will be IQ, second will be ergonomics, and third will be price. But this has a chance to really innovate my kit. I am very intrigued by the potential of this TC.

Fourth will be a drop-in filter.

 

[ethanz]

The optics in the 1.0x would have to be some kind of reducer, right? Since you are extending the length from the sensor.

 

[Loswr]

The optics in the 1.0x would have to be some kind of reducer, right? Since you are extending the length from the sensor.

Correct. I suspect the optics needed are non-trivial. For example, the FD-to-EOS converter from Canon was actually a 1.26x TC. Similarly, the available 3rd party FD-to-EOS converters are typically 1.4x, as are the M42-to-Nikon-F, for example.

In addition to being non-trivial, I suspect that 1x optics would not 'stack' well with 1.4x and 2x, since the extender(s) would have to overcome the reducer, i.e. need to be higher mag than 1.4x to achieve 1.4x. A design where the 1.0x flips out and the 1.4x/2x flip in would accomplish that, but that would be a lot of glass to shift around.

OTOH, a design comprising a 1.4x TC with an additional set of 1.4x 'flip-in' optical elements making it 2x would be straightforward. Really not holding my breath for a 1/1.4/2x switchable, I'm thinking a 1.4x/2x switchable TC is the more likely option. Happy to be wrong.

 

[scyrene]

The existing RF teleconverters aren't exactly cheap! Interesting concept though, I wonder why zoom extenders haven't been done before (unless they have?).

 

[domo_p1000]

That is a very positive development and hopefully one that given time and continued R&D by the various lens manufacturers may also trickle down into the more sensible end of the market.

 

[usern4cr]

If they have the same optical tube diameter, I don't know how they'd have the ability to swing the optics in & out to have a separate 1.0x, 1.4x and 2x TC. But if they had a larger diameter then they could do this to get the maximum IQ at all 3 settings. If they don't swing out then they have to have a single optical design with movable (in-line) elements to give the 1.0x, 1.4x and 2x options. That would make it more of a true TV zoom. I wonder how such a zoom TC could be anywhere as sharp or have high IQ as compared to a separate 1.4x or 2x TC which were designed for just those TC values. Maybe they're using more exotic (& expensive) lens & coating materials?

 

[Loswr]

The existing RF teleconverters aren't exactly cheap! Interesting concept though, I wonder why zoom extenders haven't been done before (unless they have?).

Long ago, Kenko made a 2x/3X converter (for M42 and Nikon F, I think). It was a two-part thing with an extension tube behind the teleconverter with optics in the converter spring-loaded to pop backward in to the extension tube to change the magnification.

Probably flogging a deceased equine here, but I think this rumor is a conflation of a recent Canon patent that looks quite practical but also looks a lot like a 1.4x/2x combination with an older patent for a 1/1.5/2x adapter that has just 4 elements in two groups, with one group able to move to change the magnification. That older patent is quite simple:



Seems like far too simple a design for what's being discussed here. The actual text of the patent states the purpose as, "In the adapter device, if the imaging area of the image sensor in the camera device and the image circle of the lens device do not match each other, or if the mount of the camera device and the mount of the lens device do not match each other, the camera device and the lens device It can be attached between. In addition, the adapter device can be used to connect the camera device and the lens device with the interface that is not aligned with each other, and to convert the flange back length of the lens device."

This looks far more like a mount conversion adapter to accommodate different sensor sizes than an actual teleconverter. There are embodiments in the patent where instead of magnification the adapter includes a variable ND filter, image stabilization, etc. Seems aimed more at video, actually. The 'magnification' that people seem to assume implies a teleconverter function seems more like adjusting the image circle of the lens to match the image circle appropriate for the sensor, i.e. it's adjusting for a crop factor of 1x to 2x. Either way it's a general purpose adapter patent, not a teleconverter design.

OTOH, compare the above simplistic design to what actually looks like a switchable TC design from the more recent patent:


This design has one 'base' option with a set of swing-in elements, i.e. only two settings. Could be 1x/2x, 1x/1.4x, to 1.4x/2x, but given that as stated above 1x is actually a reducing optic that opposes the magnification of a TC, I think a dual option including 1x is unlikely.

I get it, the idea of a 1x/1.4x/2x switchable TC sounds amazing.



Sorry to be that guy, but...

 

[SwissFrank]

Canon RF plus a mention of "It won't be cheap" will move it into the $2000+ range. At some point it will be cheaper to get a new body with more megapixels instead of a TC.

The RF lenses are fantastic sharpness but I bet lens sharpness will also be a limiting factor to how much you can crop-to-zoom, even with a billion pixels...

 

[SwissFrank]

Wouldn´t it be advantegeous for Canon to make it compatible with other RF-glasses as well ?

I'm an engineer but don't know enough optics to be able to state you could do a great job with a one-size-fits-all TC. Maybe you can, maybe you can't. I just don't know how they work, really, on an optics level.

I hope that if they make dedicated TC's for various lenses they still work OK-ish with other lenses too. On EF, you could actually stack both TCs together, maybe with an extension tube, though I never did resolution tests of the resulting monster.

 

[Pastrami]

Changing the teleconverter for each lens is troublesome. It would be nice to be able to use RF70-200mm and RF100-500mm.