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Lens Extender compatibility with EOS 5D Mark IV and EF 70-200 f/2.8L IS II USM lens


I have a 5d mark iv and a 70-200 f2.8 ii lens. I want to buy a 1.4 and/or 2x extender. I know there are mark ii and mark iii versions. Not sure which is compatible with the gear I have. Is there a difference and will the mark ii work just as good as the mark iii or what? I know I can get the mark iii new and the mark ii I can get used from someone but want to know what is the difference and compatibility before purchasing either.



I think mine is a Mk II and for what its worth it is one of the few applications where I think a 1.4x tel-con is a good idea. I don't like the 2x which I wasted money on buying one years ago and never use and never recommend anyone else buy one. Oh, I have the Mk II lens. I think either one will work on a either lens.

BTW, the only other lens I think is a good match for the 1.4x tel-con is the ef 300mm f4L lens.

EOS 1DX and 1D Mk IV and less lenses then before!

Why don't you like the 2x? Yea, I think I have the same lens 70-200mm f/2.8L IS II USM. I think they have the mark iii out now but mine works great still. So you think 1.4x giving a 70-200 a 98-280mm zoom is fine for shooting football and even some birds and stuff around the city? I thought of buying the sigma 150-600 contemporary lens for like $899 right now on sale but just not sure how much use I'd get out of it for what I do. I'm still learning to shoot sports as well as nature etc. If I shot professionally I'd already have the money or even a big lens to do so but it will probably be a long time from now before that happens if it ever does.

How much of a difference is it between 200mm as to 280mm with the 1.4x on?


I was just gonna check around for a used 1.4x mark ii extender for around $100 - $120 or if its work spending the $430 on a brand new 1.4x mark iii extender.



And I second Ernie's recommendation.  The 1.4X works well with several lenses, I wouldn't bother with the 2X.

I have had a 1.4X II for several years and my 70-200 f2.8 IS III came with a 1.4X III as part of a promotion; I really can't see any difference between the results from the II and III.

As to the 2X, I have some of the sharpest glass Canon has made (200 f2, 300 and 400 f2.8) and in my experience the 2X results in an excessive loss of sharpness, contrast, and overall image quality.  It is a great device for turning an excellent quality lens into image results like that from a much lesser quality lens.  With recent image sensors, including that of your 5D IV, the 1.4X plus a bit of cropping will result in the same coverage with equal and generally better image quality.


EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

Ok, awesome! Thanks. Yea, I just want something with a little more reach. the 1.4x will give me a zoom of 98-280mm. I just don't wanna break the bank lol. getting a longer zoom even the sigma 150-600mm for $899 is a little much. I don't live in an area where there is a bunch of wildlife other than going to a zoo. So birds and whatnot is about it for me. So can't see spending that kind of money on one that big right now. 

Yea, I wanted to make sure my gear was still compatible with the 5d mark iv and the 1.4x mark ii or 2x mark ii extenders and what the big difference was between mark ii and mark iii extenders if any.

I was just gonna check around for a used 1.4x mark ii extender for around $100 - $120 or if its work spending the $430 on a brand new 1.4x mark iii extender.


My opinion of extenders differs from others.

I use EF100-400mm f/4.5-5.6L IS II USM +2x III for wildlife that I cannot get close to. The "digital lens optimizer" in the free to download Canon DPP software knows about it and can correct the small aperture diffraction blur if there is not too much noise. One gets four times as many pixels on the bird with the extender compared to without the extender when one cannot get closer. Richarson/Lucy deconvolution corrects small aperture diffraction blur in images from telescopes, cameras, and microscopes and is implemented in the GMIC plugin for gimp and in the "capture sharpening" of rawtherapee, but if your software does not do it or if you have too much high ISO noise then you will still have small aperture diffraction blur which depends only upon F number.

The disadvantages to using the extender:

  1. Aperture is smaller so less light and more small aperture diffraction blur
  2. For a distant subject, the light travels through more air of varying density which causes distortion, but that is distance and not the extender
  3. There is a little less contrast for small features, but that can sometimes be fixed with unsharp mask
  4. If one had more money, a longer lens is often better than using the extender
  5. If one could get closer, the bare lens would be better without the extender

The sandhill crane was flying past about 100 meters away and I was hand holding the camera. Screen capture when viewing at 100%. F/13, ISO 1000, 800mm, 1/800 second.



Sandhill Crane (Antigone canadensis) at Salt Plains National Wildlife Refuge in Oklahoma, United States on November 2, 2023 , EF100-400mm f/4.5-5.6L IS II USM +2x III , Distance about 100 metersSandhill Crane (Antigone canadensis) at Salt Plains National Wildlife Refuge in Oklahoma, United States on November 2, 2023 , EF100-400mm f/4.5-5.6L IS II USM +2x III , Distance about 100 meters

Yea i use Lightroom and photoshop for most my edits.


l though I can get a used 1.4x for about $240 or so on ebay or other places. Again jsut wanna make sure my 70-200 mark ii lens and 5d miv body is compatible and will work well with the 1.4x mark iii or even mark ii which ever I decide based on you all's recommendation.


You definitely want to use the EF 1.4x III with that lens on any Canon DSLR.

For a more detailed explanation of what results to expect, do a search for “lens groups” in the 5F4 Advanced User Guide.  If you only use the Center AF point, then you will not notice much of a s difference when it comes to AF speed and performance.

"The right mouse button is your friend."

Where's the advanced user guide? I don't see that on their website.

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