Lensrentals.com: Canon RF 600mm f/11 IS STM Teardown

Aug 1, 2020
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AlanF

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Aug 16, 2012
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The 1.4x on my 600 resolves fairly well. See the link someone gave above to my post on FM Forums about the combo. I don’t doubt that the 100-500 with the 1.4x will be better (I should receive my copy Friday, fingers crossed), but on the R at least, the 600 + 1.4x is better than I expected.
I had seen your post when browsing FM. Adding the 1.4xTC will give you higher magnification but little or no more resolution, depending on the number of megapixels on your sensor. You could try an experiment to check for yourself. Take the same scene with and without the 1.4xTC, then upresolve the bare lens image using decent software like Topaz Gigapixel or maybe even Photoshop. On the lower resolution R6, there may be a very modest increase in resolution but with the R5 you won't see it. If you don't believe my calculations, take a look at MTFs measured by ePhotozine for lenses on the the 5DSR. As they stop down from f/11 to f/16, the MTFs drop on average by a factor of 1.25. So, an increase of 1.4x in focal length on adding the TC is accompanied a decrease of 1.25x to give a net gain of 12% in resolution if the TC doesn't add any aberration - and it will add aberration.
So, if you are thinking of shelling out $500 or so on a TC for the f/11 lenses, save your money and buy some cheaper software instead to magnify your images digitally. I am saying this for the narrow f/11 lenses where diffraction is all important, the TCs will be fine on wide aperture lenses.
 
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Vast majority of monitors today are 1920x1080 (~2.07 Mpx)
And if we assume one shoots 3:2 aspect, it also includes black borders on the sides.
In this case, image sharpness comes mainly from the lens resolving power.
Vast majority sold today, probably true. Vast majority in use - well not when I googled it based on web stats, it is considerably lower. A lot of (older) smartphones don't do that resolution...
 

SteB1

EOS M50
Feb 22, 2019
38
49
I'm not sure what to think about these lenses. The perspective I'm looking at them is from that of the wildlife/nature photographer. Most such photographers are probably already going to have a 400mm or similar option. So to me the most interesting question is how these compare to a 400mm option (I'm talking about f5.6 not f2.8) and a teleconverter, or extender in Canon language. Either 1.4x for the 600mm version and 2x for the 800mm version. Luckily on The Digital Picture both lenses have been added to the comparison tool. It was a bit disappointing. The 1.4 extender added to a any of the Canon 400mm f5.6 lenses is much better optically than the 600mm f11 and provides 40mm more focal length, gives f8, rather an f11, plus leaves you with a 400mm 5.6. A similar story with the 2x extender. So if you've already got one of the 400mm f5.6 lenses, I think you'd be better of carrying one of them with extenders.
 

BeenThere

EOS R
CR Pro
Sep 4, 2012
1,194
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I'm not sure what to think about these lenses. The perspective I'm looking at them is from that of the wildlife/nature photographer. Most such photographers are probably already going to have a 400mm or similar option. So to me the most interesting question is how these compare to a 400mm option (I'm talking about f5.6 not f2.8) and a teleconverter, or extender in Canon language. Either 1.4x for the 600mm version and 2x for the 800mm version. Luckily on The Digital Picture both lenses have been added to the comparison tool. It was a bit disappointing. The 1.4 extender added to a any of the Canon 400mm f5.6 lenses is much better optically than the 600mm f11 and provides 40mm more focal length, gives f8, rather an f11, plus leaves you with a 400mm 5.6. A similar story with the 2x extender. So if you've already got one of the 400mm f5.6 lenses, I think you'd be better of carrying one of them with extenders.
400mm + 1.4X = 560mm. But generally agree with your conclusions.
 
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AlanF

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Aug 16, 2012
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I'm not sure what to think about these lenses. The perspective I'm looking at them is from that of the wildlife/nature photographer. Most such photographers are probably already going to have a 400mm or similar option. So to me the most interesting question is how these compare to a 400mm option (I'm talking about f5.6 not f2.8) and a teleconverter, or extender in Canon language. Either 1.4x for the 600mm version and 2x for the 800mm version. Luckily on The Digital Picture both lenses have been added to the comparison tool. It was a bit disappointing. The 1.4 extender added to a any of the Canon 400mm f5.6 lenses is much better optically than the 600mm f11 and provides 40mm more focal length, gives f8, rather an f11, plus leaves you with a 400mm 5.6. A similar story with the 2x extender. So if you've already got one of the 400mm f5.6 lenses, I think you'd be better of carrying one of them with extenders.
I don't know what body you are using to make the comparisons. The 5DSR is the most appropriate comparison on TDP for the R5 as they have similar output sizes for the TDP charts. The 800 f/11 is actually quite similar to the 2xTC on the 500/5.6 prime. As I have an excellent 100-400mm II and a set of TCs, I am sticking with those for my on-order R5 - zoom and 1m mfd, as well as 400/5.6 for BIF.
 
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Dragon

EF 800L
May 29, 2019
260
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DPR just put up samples for the 600 and went to the opposite extreme for SS and ISO compared to what they did for the 800. Both lenses are decently sharp for f/11 and have minimal CA, so they should clean up quite well with proper processing. I suspect the biggest problem many buyers who are buying on price will encounter is the atmospheric challenge of getting decent distance shots with a long lens, no matter how good the glass is. Personally, I am looking forward to see how much the IBIS in the R5 improves the handling of my 1000mm Nikon mirror lens.
 

AlanF

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Aug 16, 2012
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And this is what TDP writes about using extenders on the 600/11

"The addition of a 1.4x Extender to the RF 600 creates an attractive 840mm IS lens. Extend the focal length without increasing the aperture opening, and the effective aperture is reduced — by 1-stop with the 1.4x mounted. Few are going to find f/16 attractive for most 840mm uses with diffraction impact showing even on lower-resolution R-series cameras. Magnifying the image and adding optics to the path are not helpful from an image quality perspective. That said, in bright light, the 840mm results from this lens can be usable.
The addition of a 2x Extender creates an impressive-sounding 1200mm focal length lens. In this case, the aperture is reduced 2-stops to a dauntingly-narrow f/22. Autofocusing that combination is a superpower of some R-series cameras, including the Canon EOS R5 and Canon EOS R6. Adding the 2x extender to the optical formula significantly degrades image quality — here is the comparison. The RF 2x adds a small amount of barrel distortion to the image and magnifies (blurs?) the lateral CA. While this combination works, I recommend getting closer without the 2x mounted."
 
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highdesertmesa

EOS R6 | GFX 50R
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Apr 17, 2017
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I had seen your post when browsing FM. Adding the 1.4xTC will give you higher magnification but little or no more resolution, depending on the number of megapixels on your sensor. You could try an experiment to check for yourself. Take the same scene with and without the 1.4xTC, then upresolve the bare lens image using decent software like Topaz Gigapixel or maybe even Photoshop. On the lower resolution R6, there may be a very modest increase in resolution but with the R5 you won't see it. If you don't believe my calculations, take a look at MTFs measured by ePhotozine for lenses on the the 5DSR. As they stop down from f/11 to f/16, the MTFs drop on average by a factor of 1.25. So, an increase of 1.4x in focal length on adding the TC is accompanied a decrease of 1.25x to give a net gain of 12% in resolution if the TC doesn't add any aberration - and it will add aberration.
So, if you are thinking of shelling out $500 or so on a TC for the f/11 lenses, save your money and buy some cheaper software instead to magnify your images digitally. I am saying this for the narrow f/11 lenses where diffraction is all important, the TCs will be fine on wide aperture lenses.
I'll try it for sure. Do you think the unusual f/11 lens design (DO + fewer elements + odd element placement) could change the way these lenses resolve with a TC?
 

highdesertmesa

EOS R6 | GFX 50R
CR Pro
Apr 17, 2017
304
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And this is what TDP writes about using extenders on the 600/11

"The addition of a 1.4x Extender to the RF 600 creates an attractive 840mm IS lens. Extend the focal length without increasing the aperture opening, and the effective aperture is reduced — by 1-stop with the 1.4x mounted. Few are going to find f/16 attractive for most 840mm uses with diffraction impact showing even on lower-resolution R-series cameras. Magnifying the image and adding optics to the path are not helpful from an image quality perspective. That said, in bright light, the 840mm results from this lens can be usable.
The addition of a 2x Extender creates an impressive-sounding 1200mm focal length lens. In this case, the aperture is reduced 2-stops to a dauntingly-narrow f/22. Autofocusing that combination is a superpower of some R-series cameras, including the Canon EOS R5 and Canon EOS R6. Adding the 2x extender to the optical formula significantly degrades image quality — here is the comparison. The RF 2x adds a small amount of barrel distortion to the image and magnifies (blurs?) the lateral CA. While this combination works, I recommend getting closer without the 2x mounted."
Not surprised the 2x did not yield great results – the RF 2x has already been reported to be no better than the EF 2x III, whereas the 1.4x is an improvement over the latest EF 1.4x.

FWIW, I bought the 1.4x for the RF 100-500 I have on order – I've been messing around with using it on the 600 in the meantime. Even if there are modest resolutions gains with the 1.4x on my R+600, the price of the TC wouldn't have made sense at about 70% of the price of the lens.
 
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AlanF

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Aug 16, 2012
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I'll try it for sure. Do you think the unusual f/11 lens design (DO + fewer elements + odd element placement) could change the way these lenses resolve with a TC?
I doubt it. The f/11 lenses are nice for what they are and will have many happy users. I find TCs less and less useful as the resolution of my camera sensors have increased increasing the demands on lens IQ and the negative effects of diffraction. The TCs are really overpriced too.
 
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melgross

EOS RP
Nov 2, 2016
603
396
I'm going to assume you meant "good" not "goo" :D

Up front I'll say I have no interest in this lens...but it sounds like Canon decided to build a lens that does exactly ONE thing very well, and this is the result. For those who happen to need that one thing, it looks like a great deal.
Sometimes, after I check my post before I upload it, it’s fine, but later when I read what was posted, it’s not. I have that problem with a small number of sites. I don’t know where the problem is coming from. This post is perfect now, we’ll see if it remains so.
 

AlanF

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Aug 16, 2012
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Sometimes, after I check my post before I upload it, it’s fine, but later when I read what was posted, it’s not. I have that problem with a small number of sites. I don’t know where the problem is coming from. This post is perfect now, we’ll see if it remains so.
I have the same problem, but it's not the site, it's my sight - not as good as it used to be.
 

Bert63

EOS RP
CR Pro
Dec 3, 2017
772
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See, you are phrasing this as a negative, but what I see is "This $900 lens outperforms the $2200 100-400mm with the $430 2x TC ($2630 total)." That seems like a win for a consumer lens with a lot of reach in an affordable, compact package.
I've never seen an image come out of a 100-400L II w/2X that looks even remotely close to a keeper.
 

Bert63

EOS RP
CR Pro
Dec 3, 2017
772
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The 1.4x on my 600 resolves fairly well. See the link someone gave above to my post on FM Forums about the combo. I don’t doubt that the 100-500 with the 1.4x will be better (I should receive my copy Friday, fingers crossed), but on the R at least, the 600 + 1.4x is better than I expected.
You think the 100-500 is shipping Friday?
 

CanonFanBoy

Real men single speed.
CR Pro
Jan 28, 2015
5,119
3,258
Irving, Texas
I'm not sure what to think about these lenses. The perspective I'm looking at them is from that of the wildlife/nature photographer. Most such photographers are probably already going to have a 400mm or similar option. So to me the most interesting question is how these compare to a 400mm option (I'm talking about f5.6 not f2.8) and a teleconverter, or extender in Canon language. Either 1.4x for the 600mm version and 2x for the 800mm version. Luckily on The Digital Picture both lenses have been added to the comparison tool. It was a bit disappointing. The 1.4 extender added to a any of the Canon 400mm f5.6 lenses is much better optically than the 600mm f11 and provides 40mm more focal length, gives f8, rather an f11, plus leaves you with a 400mm 5.6. A similar story with the 2x extender. So if you've already got one of the 400mm f5.6 lenses, I think you'd be better of carrying one of them with extenders.
The EF 400mm f/5.6L has been discontinued.
 

SteB1

EOS M50
Feb 22, 2019
38
49
The EF 400mm f/5.6L has been discontinued.
I still see it for sale new. However, this wasn't my point. I was clearly referring to already existing Canon wildlife and nature photographers who already have a 400mm f5.6 lens (not necessarily the prime). When I compared the lens on the comparison tool on The Digital Picture I included the mk1 100-400mm, even though I use the mkII version. So the point I was making is whether it would be worth a pre-existing Canon wildlife photographer getting one of these lenses, or just using the 400mm lens they already have with an adapter and an extender. A 2x extender on a 400mm f5.6, whether the prime or one of the zooms will give an 800mm f11 and a 1.4x extender would give a 640mm f8.
 

SteB1

EOS M50
Feb 22, 2019
38
49
I don't know what body you are using to make the comparisons. The 5DSR is the most appropriate comparison on TDP for the R5 as they have similar output sizes for the TDP charts. The 800 f/11 is actually quite similar to the 2xTC on the 500/5.6 prime. As I have an excellent 100-400mm II and a set of TCs, I am sticking with those for my on-order R5 - zoom and 1m mfd, as well as 400/5.6 for BIF.
I used the 5DSR body on the TDP comparison as the resolution was similar to the R5. I agree with the other points and of course the MFD will be much better.