# Patent: Canon continues development of EF supertelephoto lenses



## Canon Rumors Guy (Jan 23, 2020)

> In a patent uncovered by Canon News, it appears Canon is continuing the development of EF telephoto lenses. This patent is related to the focusing speed of the lenses as well as the reduction in aberrations.
> *Canon EF 300mm f/2.8L IS USM*
> 
> Focal length: 294.00mm
> ...


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Continue reading...


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## Antono Refa (Jan 23, 2020)

I'm not so sure this means Canon is continuing R&D of EF lenses. Possibly R&D was stopped and announcement was made while the patent filing and publishing bureaucracy was in the works. I wouldn't be surprised if Canon decided to release a new 1Dx mkIII & new super teles so the market would be satisfied while it developed a new sports RF camera & lenses.


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## koenkooi (Jan 23, 2020)

Antono Refa said:


> I'm not so sure this means Canon is continuing R&D of EF lenses. Possibly R&D was stopped and announcement was made while the patent filing and publishing bureaucracy was in the works. I wouldn't be surprised if Canon decided to release a new 1Dx mkIII & new super teles so the market would be satisfied while it developed a new sports RF camera & lenses.



The 400mm and 600mm are a year old, so maybe they'll just release the 300, 500 and 800?


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## Tom W (Jan 23, 2020)

I have the 500/4 II, which is absolutely a stellar lens. But for my shooting, I rarely use it. I tend to walk around when shooting nature (mostly birds) and thus find, despite its reduced image quality, my Sigma 150-600 is about the best tool for that job. Relatively light and zoomable.

These new lenses, with the weight back closer to the camera body, would be a welcome upgrade. Although the 600/4 III is lighter than my 500 already.

Now, apply that design technology to something like the 200-400 f/4 with the 1.4X built in and my might have a very high quality, manageable birding/walkabout lens.


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## Del Paso (Jan 23, 2020)

DSLR's are far from being dead, why should development of EF lenses be discontinued?


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## GMCPhotographics (Jan 23, 2020)

Del Paso said:


> DSLR's are far from being dead, why should development of EF lenses be discontinued?


I'm guessing the top tier pro lenses (ie over $5K) will remain in the EF development portfolio until Canon has a pro (sports / wildlife) mirrorless body offering. At the moment, I can't see many sports guys jumping over to the Rf mount when the Eos R is the only semi-pro body available. The 1Dx range is still king in Canon world.


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## AlanF (Jan 23, 2020)

Tom W said:


> I have the 500/4 II, which is absolutely a stellar lens. But for my shooting, I rarely use it. I tend to walk around when shooting nature (mostly birds) and thus find, despite its reduced image quality, my Sigma 150-600 is about the best tool for that job. Relatively light and zoomable.
> 
> These new lenses, with the weight back closer to the camera body, would be a welcome upgrade. Although the 600/4 III is lighter than my 500 already.
> 
> Now, apply that design technology to something like the 200-400 f/4 with the 1.4X built in and my might have a very high quality, manageable birding/walkabout lens.


My shooting style with nature and birds is the same as yours. It's a pity for us that they are not going in for some lightweight f/5.6 primes. I've added a Nikon 500/5.6 PF to my gear (couldn't resist a bargain) and it's a joy walking around with a 1.46kg lens, even lighter than my much loved 100-400mm II.


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## AccipiterQ (Jan 23, 2020)

That 800 is only 2% longer than the 600.......Don't tease me canon


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## Tom W (Jan 23, 2020)

AlanF said:


> My shooting style with nature and birds is the same as yours. It's a pity for us that they are not going in for some lightweight f/5.6 primes. I've added a Nikon 500/5.6 PF to my gear (couldn't resist a bargain) and it's a joy walking around with a 1.46kg lens, even lighter than my much loved 100-400mm II.



I'd really like Canon to answer the Sigma/Tamron 150-600, even if it's 200-600. The 200-400 f/4 with the built in teleconverter is very good and very convenient, but more costly than I'm willing to pay. It's definitely a better lens than my Siggy, but I'm not a pro and am not making any money to speak of with my photos.

Nikon has, I think, a 200-500 f/5.6 lens. That extra 1/3 stop is welcome, even if it isn't much. Helpful when using a crop sensor where ISO 12,800 is pretty doggone rough.


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## Tom W (Jan 23, 2020)

GMCPhotographics said:


> I'm guessing the top tier pro lenses (ie over $5K) will remain in the EF development portfolio until Canon has a pro (sports / wildlife) mirrorless body offering. At the moment, I can't see many sports guys jumping over to the Rf mount when the Eos R is the only semi-pro body available. The 1Dx range is still king in Canon world.



I don't anticipate a great difference in the optical design between an EF and RF lens at these long focal lengths. The EF lenses have a pretty long distance between the back element and the sensor as it is. Simply redesigning the mount ought to be suitable. 

Or, making an EF-RF adapter with a 1.4X teleconverter function built in. Best of both worlds!


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## AlanF (Jan 23, 2020)

Tom W said:


> I'd really like Canon to answer the Sigma/Tamron 150-600, even if it's 200-600. The 200-400 f/4 with the built in teleconverter is very good and very convenient, but more costly than I'm willing to pay. It's definitely a better lens than my Siggy, but I'm not a pro and am not making any money to speak of with my photos.
> 
> Nikon has, I think, a 200-500 f/5.6 lens. That extra 1/3 stop is welcome, even if it isn't much. Helpful when using a crop sensor where ISO 12,800 is pretty doggone rough.


In practice as far as noise is concerned, the front diameters are 95mm for both the 500/5.6 and 600/6.3 and so they let in the same amount of light.


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## Tom W (Jan 23, 2020)

AlanF said:


> In practice as far as noise is concerned, the front diameters are 95mm for both the 500/5.6 and 600/6.3 and so they let in the same amount of light.



However, at f/6.3 as opposed to 5.6, you need to either reduce shutter speed 1/3 of a stop or increase ISO 1/3 of a stop to expose identically. 

Not really an issue on a bright day, but in the darkness of the forest, you start pushing things a bit.


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## AlanF (Jan 23, 2020)

Tom W said:


> However, at f/6.3 as opposed to 5.6, you need to either reduce shutter speed 1/3 of a stop or increase ISO 1/3 of a stop to expose identically.
> 
> Not really an issue on a bright day, but in the darkness of the forest, you start pushing things a bit.


As far as noise is concerned, it's not just a case of simply comparing f-numbers when different focal lengths are concerned. It's a similar situation to say having an f/4 50mm lens on a crop and an f/4 80mm lens on a FF. Fill the frame of each with the same scene and shoot at the same shutter speed and although both have the same f number, the crop receives only 1/2.56 of the amount of light falling on the sensor and so the noise is greater. The FF will have the same signal/noise at 1.4 stops higher iso and so you can shoot the same scene at 1.4 stops more of shutter speed and get the same quality of image.


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## Jethro (Jan 23, 2020)

Tom W said:


> Or, making an EF-RF adapter with a 1.4X teleconverter function built in. Best of both worlds!


This would be wonderful, and sell by the truckload - but probably cannibalise the individual adaptor and teleconverter sales!


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## unfocused (Jan 23, 2020)

Tom W said:


> ...making an EF-RF adapter with a 1.4X teleconverter function built in. Best of both worlds!



I second this idea. I really hope that Canon does release such a product in the next few years. As far as I'm concerned this would pretty much eliminate the need to make RF mount superteles.


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## wsmith96 (Jan 23, 2020)

unfocused said:


> I second this idea. I really hope that Canon does release such a product in the next few years. As far as I'm concerned this would pretty much eliminate the need to make RF mount superteles.



Wasn't there a rumor of a mount that would accept both RF and EF lenses without an adapter? If so, your theory above would make sense.


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## Danglin52 (Jan 24, 2020)

Antono Refa said:


> I'm not so sure this means Canon is continuing R&D of EF lenses. Possibly R&D was stopped and announcement was made while the patent filing and publishing bureaucracy was in the works. I wouldn't be surprised if Canon decided to release a new 1Dx mkIII & new super teles so the market would be satisfied while it developed a new sports RF camera & lenses.



Totally agree with your comment. These are patents that could have been in process for more than a year. Once they started the process, Canon would probably have continued so they can claim prior art and derivative patents for the RF Big Whites. I wish it was true because I would love to have a new 200-400 that is 1.5-2lb lighter. That is assuming the patents cover the 200-400 or that patents is till in the works. The 300mm II & 500mm II is already pretty light, so I don't think you would see as drastic a weight reduction as the 400 & 600. The 800 could definitely benefit.


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## Danglin52 (Jan 24, 2020)

unfocused said:


> I second this idea. I really hope that Canon does release such a product in the next few years. As far as I'm concerned this would pretty much eliminate the need to make RF mount superteles.



If you look at the 200-400 with the switch to engage the TC, I think it might be possible to create a similar switchable TC for the EF-RF adaptor. I haven't measured this out and I don't have the R + adaptor to measure. The EF-RF adaptor might be a little shorter, but I don't remember from the few times I have played with the camera. .


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## Mr Majestyk (Jan 24, 2020)

Where is the 500 f/4? Do they assume we all prefer the 600 f/4. I assume it’ll only come in RF mount, which is fine, just praying for say a 7DII mirrorless RF replacement sooner rather than later or hoping the Rs can do at least 6fps with tracking and has excellent AF.


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## Antono Refa (Jan 24, 2020)

Mr Majestyk said:


> Where is the 500 f/4?



Third sample from the top is a 500mm f/4L IS USM. The 600mm f/4L mkII was released the same year as as the 500mm f/4L mkII, and the mkIII was released last on September of last year.

Maybe those are signs a 500mm f/4L mkIII will be released soon as well.


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## degos (Jan 24, 2020)

AlanF said:


> ... the crop receives only 1/2.56 of the amount of light falling on the sensor and so the noise is greater.



Your statement is partially incorrect. The flux is lower but the irradiance is the same or higher due to being concentrated on the smaller sensor. Hence exposure is equivalent. Any additional noise artifacts are due to sensor design, not exposure.

Anyway we're talking about superteles, where people are putting the same x00mm f4 on a crop or FF so this discussion is irrelevant. The flux and irradiance is identical for both sensor sizes.


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## AlanF (Jan 24, 2020)

degos said:


> Your statement is partially incorrect. The flux is lower but the irradiance is the same or higher due to being concentrated on the smaller sensor. Hence exposure is equivalent. Any additional noise artifacts are due to sensor design, not exposure.
> 
> Anyway we're talking about superteles, where people are putting the same x00mm f4 on a crop or FF so this discussion is irrelevant. The flux and irradiance is identical for both sensor sizes.


The statement was correct. The photon noise of the image that is actually used is proportional to the square root of the flux and not the irradiance on the sensor. Circuits etc can of course produce additional noise but the poster was talking about shooting in low light where photon noise is dominant. What you have missed is that when you calculate signal to noise, dynamic range etc you do it for images that are enlarged to the same output size and the smaller sensor has to be enlarged more than a larger one. That is the reason why we get better IQ from a full frame sensor than a 2/3” although the irradiance on both sensors may have been equal. You have to enlarge a crop of the subject, say a bird, from a 500mm lens 1.2x1.2 times more than from a 600mm lens on the same sensor to give the same sized bird on screen or printed. That's equivalent to 0.5 stops advantage to the 600mm.

This is not airy fairy science, it is of practical importance and known by experience by practical photographers. If you use say a 600mm telephoto instead of a 300mm telephoto at the same f-number, after you have cropped the 300mm to the same size, not only do you have fewer pixels, the image is noisier. Also, my Sony RX10IV with its 1" sensor and 220mm f/4 lens puts the same irradiance and the same number of pixels on an image as a 600mm f/4 on a 1DX, but the Sony image becomes unusable at a relatively low iso because the image on the sensor has to be magnified 2.7x2.7 times to give the same size output as from the FF. So, don't worry about using a 1/3rd extra iso on a 600mm f/6.3 than a 500mm f/5.6 because the extra magnification takes care of the higher noise from the iso.


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## GMCPhotographics (Jan 24, 2020)

Tom W said:


> I don't anticipate a great difference in the optical design between an EF and RF lens at these long focal lengths. The EF lenses have a pretty long distance between the back element and the sensor as it is. Simply redesigning the mount ought to be suitable.
> 
> Or, making an EF-RF adapter with a 1.4X teleconverter function built in. Best of both worlds!


I think the RF gains over EF mount with the big white teles has little to do with size, weight or optics. But every thing to do with mount communication....ie AF speed & accuracy and IS capability. The Rf mount will slightly loose to the Ef mount in size and length due to the extra mount distance to the file plane relative to the mount point. But with such large lenses, it's hardly an issue. However, the coms speed between the two mounts is vastly improved with the Rf mount. It's also possible that Canon start to mount other useful buttons and controls on the White Lens body shell because the data link between the camera and lens can cope with the expansion. 
The weight reduction of the recent 600IIIL and 400IIIL have been due to moving the big elements further into the lens shell (which has also helped balance) and some lighter materials in the inner structure. These gains can be pushed only so far...so I doubt that we will see any more dramatic reductions in weight with a mk4 or Rf variant.


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## tarjei99 (Jan 24, 2020)

Since the most likely purchasers of EF x00 lenses are 1DX owners, I think it makes a lot of sense to make sure that they have the best lenses.

I'm also sure that many of the 5D owners also appreciate that their investment is being taken into account.

Those of us who owns 7Ds are also happy about this.


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## AlanF (Jan 24, 2020)

GMCPhotographics said:


> I think the RF gains over EF mount with the big white teles has little to do with size, weight or optics. But every thing to do with mount communication....ie AF speed & accuracy and IS capability. The Rf mount will slightly loose to the Ef mount in size and length due to the extra mount distance to the file plane relative to the mount point. But with such large lenses, it's hardly an issue. However, the coms speed between the two mounts is vastly improved with the Rf mount. It's also possible that Canon start to mount other useful buttons and controls on the White Lens body shell because the data link between the camera and lens can cope with the expansion.
> The weight reduction of the recent 600IIIL and 400IIIL have been due to moving the big elements further into the lens shell (which has also helped balance) and some lighter materials in the inner structure. These gains can be pushed only so far...so I doubt that we will see any more dramatic reductions in weight with a mk4 or Rf variant.


Canon does indeed claim the faster communications https://global.canon/en/imaging/l-lens/technology/rf_mount.html but I wonder if that will affect the speed and accuracy of the AF because the data being processed that appear to be rate limiting are from the image sensor and not much data has to be communicated to the drive motors in the lens.


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## Daner (Jan 24, 2020)

The total market for lenses in this price class is small enough that it makes sense to make these useful for EF, EF-S, EF-M (adapted) and RF (adapted) applications rather than segmenting them to RF only. Not that I expect too many M6 Mk. II users to be purchasing the 800mm, but now that I think about it, that combination could work well, even with 1.4 and/or 2.0 extenders.


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## Joe Subolefsky (Jan 24, 2020)

AlanF said:


> Canon does indeed claim the faster communications https://global.canon/en/imaging/l-lens/technology/rf_mount.html but I wonder if that will affect the speed and accuracy of the AF because the data being processed that appear to be rate limiting are from the image sensor and not much data has to be communicated to the drive motors in the lens.



The new 400II and 600 III already have two extra communication contacts built in that are not used with current EF bodies that canon engineers said was to future proof the lens if you read the interviews. That's why I wrote a couple months ago like others wrote in this thread I kinda expect a EF-RF adapter with a built in 1.4 extender is coming. They have already made those lens light as possible and even if such an extender cost $800-1,000 they would sell the heck out of them.


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## Joe Subolefsky (Jan 24, 2020)

http://downloads.canon.com/nw/learn/2018/articles/ef400mm-f-2.8L-IS-III-USM-EF600mm-f-4L-IS-III-USM/CUSA__updated%20Final%20lens%20developers%20interview__CUSA__11-26-2018.pdf


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## tron (Jan 24, 2020)

wsmith96 said:


> Wasn't there a rumor of a mount that would accept both RF and EF lenses without an adapter? If so, your theory above would make sense.


Let's think of this imaginary mount as ERF   But seriously it would be very convenient except for the sensor movement so I do not believe it will happen. However a 1.4X EF to RF teleconverter for big white EF teles would be very interesting assuming the camera behind them is the so called Rs.

But: Why not Canon make an adapter that is either a 1X or a 1.4X just like the embedded in 200-400?

Of course, it will have to be a very small 1.4X to fit so I do not know if it is possible but maybe it is. Back in the early nineties I had bought a Sigma 1.4X for Canon which was very slim.


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## Del Paso (Jan 24, 2020)

Joe Subolefsky said:


> The new 400II and 600 III already have two extra communication contacts built in that are not used with current EF bodies that canon engineers said was to future proof the lens if you read the interviews. That's why I wrote a couple months ago like others wrote in this thread I kinda expect a EF-RF adapter with a built in 1.4 extender is coming. They have already made those lens light as possible and even if such an extender cost $800-1,000 they would sell the heck out of them.


Can I place an order now?


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## AlanF (Jan 25, 2020)

Joe Subolefsky said:


> The new 400II and 600 III already have two extra communication contacts built in that are not used with current EF bodies that canon engineers said was to future proof the lens if you read the interviews. That's why I wrote a couple months ago like others wrote in this thread I kinda expect a EF-RF adapter with a built in 1.4 extender is coming. They have already made those lens light as possible and even if such an extender cost $800-1,000 they would sell the heck out of them.


No, tell them they would sell a gazillion at $400-500. It's a neat idea to combine an adapter and TC. But, we would still need the straightforward adapter to use the EF lens at its native focal length.


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## tron (Jan 28, 2020)

koenkooi said:


> The 400mm and 600mm are a year old, so maybe they'll just release the 300, 500 and 800?


And 300 can't be improved. So 500 and 800 with 800 being the older. But it's time they introduced new DO lenses.


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## koenkooi (Jan 28, 2020)

tron said:


> And 300 can't be improved. So 500 and 800 with 800 being the older. But it's time they introduced new DO lenses.



Canon showed a 400DO and a 600DO during the Canon expo a few years back, but went really silent about them soon after: https://www.canonrumors.com/canon-ef-600mm-f4-do-br-at-canon-expo/


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## tron (Jan 28, 2020)

koenkooi said:


> Canon showed a 400DO and a 600DO during the Canon expo a few years back, but went really silent about them soon after: https://www.canonrumors.com/canon-ef-600mm-f4-do-br-at-canon-expo/


Yes I remember this. But it weighted just like the new 600III so the only advantage would be the size. For me the size is equally important but maybe this will not happen now. The 400DOII is more than good enough (In fact it is very very good so there is no need for update).


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