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A new type of teleconverter is coming.

AmbientMike
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p.3 #1 · p.3 #1 · A new type of teleconverter is coming.

Should be able to get a few Nikon and Sony users if this comes to fruition. Idk if nikon has 1.4 and 2x in theirs not sure if Sony has internal tc's.

Having removable without removing the lens 1.4 & 2x probably appealing to many

May 27, 2023 at 12:20 PM

Photonadave
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p.3 #2 · p.3 #2 · A new type of teleconverter is coming.

My take on this newfangled zooming converter simplistic looking patent is that it continuously zooms from 1X to 2X magnification with a simple mechanical click stop (or possibly more clicks) anywhere in this range. The optical formula also allows the converter to compensate for its added fixed physical extension length allowing infinity focus in all settings. The focal lengths and their corresponding f/stops would also vary continuously as defined by the longtime established/traditional mathematical formula for the particular lens mounted.

I agree with others that it may well fit lots of other lenses as it appears to not protrude into a mounted lens in this patent documentation however I suspect that the optical performance may be tuned specifically to the new RF 100-300mm & 200-500mm lenses in addition to protruding into and keyed to fit only these two lenses for now.

Edited on May 27, 2023 at 09:30 PM · View previous versions

May 27, 2023 at 02:08 PM

NonDecaf
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p.3 #3 · p.3 #3 · A new type of teleconverter is coming.

TakesRandomPics wrote:
BTW there is a built in TC with easy switching in FF cameras - set it to crop mode. Yes you lose resolution but if you were going to crop those out anyway you don't really lose anything. There is also evidence to show that it helps with focus acquisition so technically EVERY lens has a built in TC

Yes, IMHO, either use a TC or a high-pixel density sensor, but not both.

May 27, 2023 at 04:55 PM

NonDecaf
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p.3 #4 · p.3 #4 · A new type of teleconverter is coming.

rscheffler wrote:
Question in my mind: if it spans 1-2x magnification, what will be the image quality hit by the additional optics in the light path at 1x? Is there a free lunch here to keep the TC attached at all times without optical compromises? It just doesn't seem logical for this to be true.

Down the road when Canon finally has a pro level APS-C body, how about a 0.625-1.25x speedbooster/TC combo? This way the 100-300 and 200-500 can be used at FF equivalent fields of view of 100-300 to 200-600 and 200-500 to 400-1000 respectively on APS-C. If more reach is...Show more →

So you're saying the same optical system would be capable of projecting a smaller image circle (APSC) and also a larger image circle (FF). How would it work though?

May 27, 2023 at 04:59 PM

rscheffler
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p.3 #5 · p.3 #5 · A new type of teleconverter is coming.

rscheffler wrote:
Question in my mind: if it spans 1-2x magnification, what will be the image quality hit by the additional optics in the light path at 1x? Is there a free lunch here to keep the TC attached at all times without optical compromises? It just doesn't seem logical for this to be true.

Down the road when Canon finally has a pro level APS-C body, how about a 0.625-1.25x speedbooster/TC combo? This way the 100-300 and 200-500 can be used at FF equivalent fields of view of 100-300 to 200-600 and 200-500 to 400-1000 respectively on APS-C. If more reach is...Show more →
NonDecaf wrote:
So you're saying the same optical system would be capable of projecting a smaller image circle (APSC) and also a larger image circle (FF). How would it work though?

Yes. Speed boosters already exist. But none are zoomable AFAIK. I'm suggesting Canon explore this as another option separate from the rumored 1-2x zoom teleconverter. I don't know how optically difficult it would be in reality.

IMO it would make native FF lenses so much more versatile on APS-C. I can appreciate taking advantage of APS-C for more pixels on the subject in reach limited situations. But most sports I cover are not generally reach limited and giving up the wide end of a lens like the 200-400 on APS-C would be painful. But it would also be contingent on Canon releasing an APS-C camera more aligned with the R5/R6 cameras than the R7 was. There's also the possibility that the R5 or R5II will be a better solution than such a zoomable speed booster. If the R5II comes closer to R7 pixel density, then cropping as needed would be the simpler solution.

May 27, 2023 at 08:37 PM

arbitrage
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p.3 #6 · p.3 #6 · A new type of teleconverter is coming.

NonDecaf wrote:
Yes, IMHO, either use a TC or a high-pixel density sensor, but not both.

Wiser words have never been spoken on this subject. That is exactly how I feel about TCs.

May 28, 2023 at 05:44 AM

EverLearning
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p.3 #7 · p.3 #7 · A new type of teleconverter is coming.

arbitrage wrote:
Wiser words have never been spoken on this subject. That is exactly how I feel about TCs.

But what constituted a high-pixel density sensor yesterday is not today's high-pixel density sensor, which won't be tomorrow's high-pixel density sensor? Not long ago 30mp was considered high-density, perhaps 45mp is considered so today, but tomorrow will be 60mp or 80mp or even 100mp. So I am genuinely curious as to where one draws this line and if it is a ever-moving line. I have seen photos of a bird taken with a 600mm plus 2x TC on a 30mp camera where the tiny barbules are very sharp. I have seen photos from an R5 with 500mm and 600mm, plus 2x TC, where the barbs are very sharp and even at times the barbules.

Another consideration of course is intended use. If it's for email or social media, I suspect a 2x TC on a 100mp camera would not be a problem. But what about print? Printing 12" x 18" is very different than printing 24" x 36" for example.

As a new owner of a 500mm f/4 II I am very interested in understanding the different perspectives on this topic and what are the driver(s) behind these perspectives.

May 28, 2023 at 08:17 AM

Imagemaster
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p.3 #8 · p.3 #8 · A new type of teleconverter is coming.

Both pro and amateur sports and wildlife shooters have been using TC's for more than 50 years. They used them mostly on f2.8 or f4 prime telephoto lenses. They did so, and continue to do so, because THEY prefer the results they get better than cropping.

What size original is appropriate for what size print depends on a number of factors. And what is considered suitable is up to the owner of the print, not what any Tom, Dick, or Harry has to say. Geez, it is many years ago that I had 3 foot by 5 foot prints made from 35mm Kodachrome. The client loved them, as did many visiting his office. They were loved due to the subject matter, not any sharpness factor.

The same can be said about many large prints made from the Canon EOS 5D 12.7 megapixel DSLR.

May 28, 2023 at 11:57 AM

Photonadave
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p.3 #9 · p.3 #9 · A new type of teleconverter is coming.

NonDecaf wrote:
Yes, IMHO, either use a TC or a high-pixel density sensor, but not both.

arbitrage wrote:
Wiser words have never been spoken on this subject. That is exactly how I feel about TCs.

I agree also. I stopped using them on both my 5DsR and 5DIII.

The astro enthusiasts seem to still use then a lot? Perhaps this has something to do with image stacking 100s of cherry picked images collecting as many photons as possible while adding noise reduction while they are at it?

I'm also wondering if pros and amateurs shooting high volume for big events/outings that are outputting JPG files directly out of camera to speed up or eliminate post processing may see some benefit with extenders in these situations? I dunno as I only output camera raw.

Edited to clarify 5DIII.

Edited on May 28, 2023 at 01:01 PM · View previous versions

May 28, 2023 at 12:14 PM

stanj
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p.3 #10 · p.3 #10 · A new type of teleconverter is coming.

Photonadave wrote:
I agree also. I stopped using them on both my 5DsR and III.

III what?

I think the specific combo really matters. Considering that my 5DsR doesn't have that many more pixels per duck than my R5, I can state that I prefer using the RF1.4x and RF2x TC with my RF400 over cropping, both with my R5 and (less surprisingly) R3. Similarly, I prefer using the EF1.4xIII and EF2xIII TC with my EF400DOm2 on my R5 over cropping.

May 28, 2023 at 12:37 PM

EB-1
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p.3 #11 · p.3 #11 · A new type of teleconverter is coming.

NonDecaf wrote:
Yes, IMHO, either use a TC or a high-pixel density sensor, but not both.

arbitrage wrote:
Wiser words have never been spoken on this subject. That is exactly how I feel about TCs.

That's old-fashioned thinking. Modern big tele primes and 1.4x TCs give away very little in IQ on 45-50MP FF/FX sensors. Using a 1.4x TC with a zoom or using a 2x TC obviously produce lesser results, but is significantly better than cropping in most cases.

Do you use ISO 12233:2017 or an older method for testing the lenses with and without TCs?

EBH

May 28, 2023 at 01:17 PM

EB-1
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p.3 #12 · p.3 #12 · A new type of teleconverter is coming.

EverLearning wrote:
But what constituted a high-pixel density sensor yesterday is not today's high-pixel density sensor, which won't be tomorrow's high-pixel density sensor? Not long ago 30mp was considered high-density, perhaps 45mp is considered so today, but tomorrow will be 60mp or 80mp or even 100mp. So I am genuinely curious as to where one draws this line and if it is a ever-moving line. I have seen photos of a bird taken with a 600mm plus 2x TC on a 30mp camera where the tiny barbules are very sharp. I have seen photos from an R5 with 500mm and 600mm, plus...Show more →

The 5D IV at 30MP was never considered particularly high resolution even in September 2016, since the 50MP 5DsR had already been out in June 2015 and Sony had 36 MP in 2013/42MP in 2015.

Since getting the 100-500 my default is to start with the 500/4 IS+1.4x III on a second R5 body. It is just slightly better at f/6.3 if your borkah can handle it. The 2X III will show some IQ loss, but clearly better than cropping/upsampling. At 1000mm it is more necessary to be close to the subject anyway since the atmospheric disturbance can easily degrade images.

EBH

May 28, 2023 at 02:09 PM

Photonadave
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p.3 #13 · p.3 #13 · A new type of teleconverter is coming.

stanj wrote:
III what?

I think the specific combo really matters. Considering that my 5DsR doesn't have that many more pixels per duck than my R5, I can state that I prefer using the RF1.4x and RF2x TC with my RF400 over cropping, both with my R5 and (less surprisingly) R3. Similarly, I prefer using the EF1.4xIII and EF2xIII TC with my EF400DOm2 on my R5 over cropping.

5DIII (BTW my EF extenders are Canon version IIIs and I have no experience with Canon R system yet.)

I'm thinking that the basis of my opinion is due in part to that I usually do not print my wildlife images usually shot with telephotos as large as my landscapes where of course I never use extenders and also the hassle involved with their use.

. . . expanding further . . .

When I'm having something printed really large there is less resampling up by me or perhaps by the printing service where more pixels per barn in landscapes is yielded by the higher resolution camera. I also feel that this would appliy to pixels per duck yielded by converters for larger prints of wildlife and other types of action. (Hmm, this might spark another debate about resampling?)

One thing I do like and miss with extenders, especially the 2X, is that the view thru the viewfinder of my DSLRs of small/ distant subjects is much nicer to see what the heck is going on.

Any loss if image quality caused by the use of modern converters is negligible nowadays so YMMV definitely applies if any inconvenience with their use in not an issue.

Thinking back, telephoto converters were must and well worth their inconvenience of use way back in my film days and to some extent with lower resolution DSLRs!

May 28, 2023 at 02:42 PM

NonDecaf
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p.3 #14 · p.3 #14 · A new type of teleconverter is coming.

rscheffler wrote:
Yes. Speed boosters already exist. But none are zoomable AFAIK. I'm suggesting Canon explore this as another option separate from the rumored 1-2x zoom teleconverter. I don't know how optically difficult it would be in reality.

IMO it would make native FF lenses so much more versatile on APS-C. I can appreciate taking advantage of APS-C for more pixels on the subject in reach limited situations. But most sports I cover are not generally reach limited and giving up the wide end of a lens like the 200-400 on APS-C would be painful. But it would also be contingent on...Show more →

Speed-boosters can only take a larger image circle and 'focus' it down to a smaller sensor size. The rear element projects an image circle for a specific sensor size. I'm not yet clear on what you mean by 'zoomable' speed booster.

May 28, 2023 at 08:02 PM

NonDecaf
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p.3 #15 · p.3 #15 · A new type of teleconverter is coming.

EB-1 wrote:
That's old-fashioned thinking. Modern big tele primes and 1.4x TCs give away very little in IQ on 45-50MP FF/FX sensors. Using a 1.4x TC with a zoom or using a 2x TC obviously produce lesser results, but is significantly better than cropping in most cases.

Do you use ISO 12233:2017 or an older method for testing the lenses with and without TCs?

EBH

But that just means that they're designed with a future higher MP sensor in mind, which I'm sure will come out eventually.

I don't think that the ISO chart you referenced is particularly relevant to my point, I'm mostly thinking of pure nyquist limits, and subsequently how much you can crop and still end up with a large 20, 30, 40 (?) MP file that still has tons of detail.

The chart you referenced will give you a basic idea of what resolution various imaging systems are capable of given a fixed subject distance. But most people use a TC when the subject is far away, and so you're really stressing the optics even more and it is far beyond what the ISO chart tests for. For e.g. a future 3 um X 3 um pixel size on a FF sensor (96MP) can theoretically resolve ~ 166 line pairs/mm, and the ISO chart you gave tops out at 25 line pairs/mm. We probably were able to resolve 25 line pairs/mm when we crossed 5 megapixels on a FF sensor.

But I will concede that when the subject gets further and further away, atmospherics and other factors play a large role so there isn't a free lunch there.

May 28, 2023 at 08:32 PM

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