Differences among the 2x extenders (i, ii, iii) on a 70-200mm f/2.8L IS II

Quick question guys....

I *occasionally* find myself in a setting where I need the 200-400mm range....and I'm wondering if it makes a significant difference if get the latest and greatest extender (iii) or just pick up a used copy (i or ii). I previously have just taken my 100-400mm along with me in the field, but considering I often don't even need it, it often becomes excess weight that I more and more want to shed.

My primary target is sideline sports photography during daylight hours, so I'm not overly concerned about f-stops and the like. And I have an idea of how these extenders compare to lenses like the 100-400mm and the like. I'm more curious about how things like my AF will perform between a 1st gen, 2nd gen, and 3rd gen extender when used on a 70-200mm f/2.8 IS ii lens.

I've looked through what seems like a jillion threads, and I can find all sorts of helpful info....but I couldn't find anything comparing the various 2x extenders on a 70-200mm.

Maybe this thread will help.

Most that have tried said 100-400L is better than the 70-200MKII with a 2X. But I don't have first hand experience with the combination.

Right, I'm aware of the 100-400mm vs. 70-200 w/ the 2x extender comparisons, with most thinking the 100-400mm is better. I'm more curious about i vs. ii vs. iii. comparisons w/ this particular lens, which I can't seem to find any.

If I know I'm going to need the 200-400mm, then it's an easy choice. I'm thinking about those times when the 70-200mm is good for just about everything, and I want something for the 200-400mm range "just in case"! The 100-400mm is just a lot of bulk to carry around when/if I don't even know whether I'll need it.

On the version II lens, the version III T-Cons are best performing.

If you want to save some $$ the MkII is not bad, but the MkIII was literally made for this new generation of lenses.

AF will take a hit with any of them of course.

Do not get the MkI 2X. It is not very good with zooms, and is definitely the weakest Canon T-Con for EF mount ever made.

With the 70-200 MKII you will benefit from using the MKIII extenders. Not so much from the 1.4X versions. Chances are you will be better off in the future with the newer one as well.

I used to have the Canon 2 x Mk2 extender but was never really happy with the results, admittedly I was mainly using it on F4 lenses (300 and 600mm). I traded it to get the Mk3 version and was pleasantly surprised at the difference in quality. Whilst I could get the occasional good shot in perfect light with the Mk2, with the Mk3 light was far less critical and images were better. Note I do not have any of the "Mk2" lenses which the Mk3 extenders are designed for so I didn't notice any real difference in AF speed but even the earlier model lenses showed a significant boost in IQ on my lenses.
My 70-200 F2.8 IS lens is the Mk1 version and I haven't had much luck with 2 x extenders on it - perhaps the 70-200 Mk2 may be different.
I use extenders when there is no alternative as they are always a compromise, however lenses like the 300 F2.8/400 F2.8 can produce really good results with the Mk3 2 x extender.

Just re-looked at this thread. Sorry, I forgot to actually attached the link in my first post. I just added it, but the others added the pertinent information. Sorry!

I use the Kenko, so neither of the Canon ones, and I have been happy with the results. Has anyone compared the Kenko 2x to any of the Canon ones? Ignorance is bliss in not knowing what I am missing from a $400 TC.

TeamSpeed wrote in post #17067288
I use the Kenko, so neither of the Canon ones, and I have been happy with the results. Has anyone compared the Kenko 2x to any of the Canon ones? Ignorance is bliss in not knowing what I am missing from a $400 TC.

A better Bokeh ?

More seriously, your Kenko looks quite sharp

I was using a 70-200 f/2.8 II and a x2 TC III yesterday in AI Servo on a 7D to track a kestrel in flight (good light) and it focused on the bird without any problems. It was very quick to focus even when the bird flew from a grassy area with lots of bushes etc in the background (low contrast). The MK II TC never performed as well for me. The weight could be an issue though. I'd imagine that the 100-400 would be lighter to use rather than this combination and I haven't tried it in low light conditions either.

Miki G wrote in post #17067431
I was using a 70-200 f/2.8 II and a x2 TC III yesterday in AI Servo on a 7D to track a kestrel in flight (good light) and it focused on the bird without any problems. It was very quick to focus even when the bird flew from a grassy area with lots of bushes etc in the background (low contrast). The MK II TC never performed as well for me. The weight could be an issue though. I'd imagine that the 100-400 would be lighter to use rather than this combination and I haven't tried it in low light conditions either.

Why would the mkiii work better with AF over the mkii? Isn't the TC just a pass-through from body to lens?

Teamspeed it (at least the MKIII models) is now not just a pass through. It says here there is an microcomputer for seamless communication.

I read somewhere else (couldn't find or I would have linked) that this actually improves the communication (and therefore performance) compared to previous models, especially between the TC and the new super-teles MKIIs.

Interesting, they must have improved back and forth communications, and any closed-loop AF cross-talk.

I wonder what is inside my Kenko? AF was okay with the 2x on the 70-200, but I could see a bit of slowness. IQ is okay though, a slight loss of contrast that I have to fix during post.

jimewall wrote in post #17067938
Teamspeed it (at least the MKIII models) is now not just a pass through. It says here there is an microcomputer for seamless communication.

I read somewhere else (couldn't find or I would have linked) that this actually improves the communication (and therefore performance) compared to previous models, especially between the TC and the new super-teles MKIIs.

Everyone keeps forgetting that the EF 70-200 2.8 IS II is NOT one of the new "Series II" Super Telephoto Lenses. There is no additional communication.

TeamSpeed wrote in post #17067986
Interesting, they must have improved back and forth communications, and any closed-loop AF cross-talk.

I wonder what is inside my Kenko? AF was okay with the 2x on the 70-200, but I could see a bit of slowness. IQ is okay though, a slight loss of contrast that I have to fix during post.

I don't know if it is the same, but it supposedly also has some new circuitry - see here.

I do want to get one of the new Kenko X models. Someone somewhere said it keeps AF with the 100L, no other TC does (it continually hunts with other TCs regardless if 1.4X or 2X - including Canon's with an ET). This would add more use for non macro shooting with the 100L (for me) if true.

msowsun wrote in post #17068017
Everyone keeps forgetting that the EF 70-200 2.8 IS II is NOT one of the new "Series II" Super Telephoto Lenses. There is no additional communication.

I did not reference it, because I did not, and do not, know if it falls under the improvement! Are you saying it does or doesn't?