# Extender 2x III on 600mm 4.0 lens - recommendable?



## xps (Aug 14, 2016)

Your experience is needed, please:

Do you use the 2x extender III on the 600mm 4.0 IS II lens? How does the 2x extender affect the image quality.

I like to shoot small birds, that are often far away. For this, I recently use the 1.4x extender and the 7DII. But often, the cropped picture is to small in my opinion.
So I would suggest to buy an 2x extender and an 80D to get maximal focal length and AF performance. Later an 5DIV will follow....

Edit: 600mm L IS 4.0 II lens


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## Mt Spokane Photography (Aug 14, 2016)

The 600mm f/4 L does not take extenders well, a 2X in particular gives noticibly softer images, or at least mine did. The IS versions do much better.


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## Freddie (Aug 14, 2016)

The 2X TC III works very well on all the late super telephoto lenses. The 2X TC II did not work well at all. Don't let some of the answers fool you as they may be referring to the earlier version.
Any loss of IQ is minimal and certainly better than enlarging the image.


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## Mt Spokane Photography (Aug 14, 2016)

Freddie said:


> The 2X TC III works very well on all the late super telephoto lenses. The 2X TC II did not work well at all. Don't let some of the answers fool you as they may be referring to the earlier version.
> Any loss of IQ is minimal and certainly better than enlarging the image.



I have the 2X TC Ver III, and on my 600 f/4 (Non IS that the topic apparently refers to), it did not work well. Can you post some photos with yours? I get sharp results with no TC and with other lenses. I've also owned Ver I and Ver II. The difference between I and II was Zero, but III is slightly better.

The Version III was supposed to speed up AF on the 600mm f/4L IS II and did improve the resolution noticibly compared to the Ver II.


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## Freddie (Aug 14, 2016)

Although the headline is vague, the text from the original poster referred to the 600 II. From what I have read, the main improvement in using the TC III with the series II super telephoto lenses was in the form of more consistently accurate focusing. I haven't heard of any great speed improvement but I could have missed it somewhere.
I was not a fan of the 2X TC II but the 2X TC III was a large improvement and works very well.


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## seanature (Aug 15, 2016)

I don't hesitate to use the 2x III extender on my 600 f/4 IS — the original IS version, which is one generation older than yours. There is a bit of an impact to image quality, but I think it's better than significantly cropping the image. I've tried to attach a 100% crop of this image, which was captured with the Canon 1D Mark IV, 600 f/4 IS, and the 2x III extender:
http://livingwilderness.photoshelter.com/image/I00007LQBmvR0Rm0






I think the bigger impact is to autofocus. It's a bit slower to acquire initial focus, but overall, I'm pleased with the results. I'm even happier with this combo on the 1Dx Mark II, which lets me use all AF points, although the AF isn't quite as snappy as with the lens by itself.


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## Mt Spokane Photography (Aug 15, 2016)

Freddie said:


> Although the headline is vague, the text from the original poster referred to the 600 II. From what I have read, the main improvement in using the TC III with the series II super telephoto lenses was in the form of more consistently accurate focusing. I haven't heard of any great speed improvement but I could have missed it somewhere.
> I was not a fan of the 2X TC II but the 2X TC III was a large improvement and works very well.



I believe he revised the text to change it to the IS II Version. 

Certainly, if you have a lens this expensive, there should be no reason to get anything but the Version III TC.


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## Freddie (Aug 15, 2016)

Here is a shot from a 500 II + 2X TC III on a 5D MK III last spring. This is about 80% of full frame.
ISO 200, 1/250 @ f/8 +1 EC (wide open).


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## neuroanatomist (Aug 15, 2016)

The 600 II does well with the 2xIII, a little loss of IQ but IMO better than an even deeper crop. Since you mention distant subjects, this a crop to a 5 MP image (click for larger).

_"Hello, My Name is Gene Simmons"_



EOS 1D X, EF 600mm f/4L IS II + EF 2x III Extender, 1/2500 s, f/11, ISO 2000


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## Eldar (Aug 15, 2016)

I can only add to those who say that the 600 f4L IS II + 2xIII works well from an IQ perspective, provided you are able to focus properly
. 
However, put on a crop camera this combo is a total nuisance to work with. With such a long reach, it is almost impossible to find anything but dead objects in the viewer. You mention small birds ... I may not be the fastest or most experienced user of this combo (I only use full frame though), but at that focal length, on a crop sensor, with the limited AF functionality you’ll have … I doubt you will get a single picture worth having. 

If you have a 600 f4L IS II, you should go full frame. Everything about your photography will benefit from that. Rent a 1DX-II, compare results to your 7DII (or any other crop) and see for yourself. With the investment you have made in lens and extenders, plus the required (dead stable and expensive) tripod/gimbal combo, makes a good full frame camera a reasonable cost. Second hand 1DXs are quite cheap these days, and if funding is available, a 1DX-II would be even better, especially for its improved AF at f/8).


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## axtstern (Aug 15, 2016)

The post mentions the 80D
A word of warning:
I tried the ef 400 2.8 l non is with my ef 2.0 (don't know if it is II or III)
That worked fast and fine.
Afterwards I tried the ef 2.0 with the ef 300 4.0 and while it should at least give me AF in the centerpoint I die not manage to get any AF on The 80D


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## daniela (Aug 15, 2016)

Hi Erik!

I am using the double extender on the Canon 500mm L 2 lens and the image quality is slightly worse than with the 1.4 times extender. 
I shoot with 7D Mark II and 5D Mark III. I tried the 80D. From the point of image quality, the 5D Mark III and the 80D are noticeably better than the 7D Mark II. The AF speed is best at the 80D, where you can use nearly 30 AF points. At the 7D and 5D the center point and the surronding 4 AF points can be used. My personal experience is: AF works on 80D precisly, but lacks a little bit of speed when you follow fast animals. But you can compose better by having a lot working AF points. The 5d and 7D AF follows better on moving animals, but you are limited by the center point. 

From my point of view (wildlife beginner) get the double extender and buy and 80D or better the coming 5D Mark IV. The 1DX Mark II is an terrific body, but an overkill for beginners needs.

Best wishes
Daniela


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## xps (Aug 15, 2016)

Thank you for your answers. I see it is worth to order one.
I will see how good the 5DIV will be and decide then which body to take.


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## Diko (Aug 15, 2016)

Thank you for the info.


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## tron (Aug 25, 2016)

Eldar said:


> I can only add to those who say that the 600 f4L IS II + 2xIII works well from an IQ perspective, provided you are able to focus properly
> .
> However, put on a crop camera this combo is a total nuisance to work with. With such a long reach, it is almost impossible to find anything but dead objects in the viewer. You mention small birds ... I may not be the fastest or most experienced user of this combo (I only use full frame though), but at that focal length, on a crop sensor, with the limited AF functionality you’ll have … I doubt you will get a single picture worth having.
> 
> If you have a 600 f4L IS II, you should go full frame. Everything about your photography will benefit from that. Rent a 1DX-II, compare results to your 7DII (or any other crop) and see for yourself. With the investment you have made in lens and extenders, plus the required (dead stable and expensive) tripod/gimbal combo, makes a good full frame camera a reasonable cost. Second hand 1DXs are quite cheap these days, and if funding is available, a 1DX-II would be even better, especially for its improved AF at f/8).


Eldar this is many times in the back of my mind although I never made comparisons when I could:

I have 500II, 1.4XIII, 2XIII 5D3 and 7D2.

500II + 5D3 Excellent (of course!) but I hadn't tested teleconverters except from one 1 in a moonrising photo behind an ancient temple. The type of (small) fringing I get can be removed 100% in ACR just only if I do not use any tc. So I did not try a tc again in that kind of shots. 

Birding:

7D2 + 500II Excellent combination (I had to AFMA but excellent).

7D2 + 500II + 1.4XIII Difficult combination. Let me explain: Even with AFMA I managed to take decent photos only when using a tripod not mainly to stop shaking (which admittedly is very important) but mainly to focus correctly. The subjects were rather far and even so I had to crop at 100% to get HD (1920x1280) images.
Still 7D2 help pretty well (It was better than nothing and the important subjects for my liking: 2 great crested crebes with a baby).

Now I did not dare to put 2XIII (with 7D2) but since everyone says that it's better to magnify rather than crop maybe I should try (but I am not sure I would get perfectly sharp pictures).

The other test I didn't try is to use 5D3 + 500 + 2X. But that would make it f/8 instead of f/5.6 and I had better stop down to get some IQ back so the loss would be more. I do not think I lost a lot.

Maybe next time I will try to do comparisons...

EDIT: Grey import 1DxII price is rather close to 5D4 price ;D


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## arbitrage (Aug 28, 2016)

I use the 600II + 2xTCIII quite a lot. I've used it on 7D2, 80D, 1DX, 5DSR and 1DX2. Works well on all of them but the AF is dramatically improved on the 1DX2 for this f/8 combo and you get to use all the 61 points which is a huge bonus (and probably the main reason I bought the MkII).

Here are a few examples...


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## XL+ (Sep 16, 2016)

I use the 2x extender quite often on the 600mm Canon II. And yes, there is an visible lower image quality. BUT the bigger size of the subject you get, is more worth than the lower image quality. If you body knows to deal with f8, the 2x extender is definitively worth buing.


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