1.4 II vs 1.4III Extender

I did a brief search and did not find an answer to my question. I currently own two bodies, the first is a 60D (that I rarely use any more) and a 5DIII that I use regularly. I own a 70-200isII and a 400 5.6. I use my 1.4II extender often with the 5dIII and the 400 5.6. While I am happy with the results, I know they could be better. Some day I hope to purchase a 500 or 600mm lens for wildlife and birding, but for now they are just not in the budget.

I read a lot about the series III extenders when they were introduced a few years ago. I am almost certain I read that with the 60D and the 400 5.6 lens it made no sense to 'upgrade' from the 1.4II I own to the 1.4 version III extender, am I correct in my assumption? Does the same hold true with my 5dIII, will I benefit with the newer version of the 1.4 (or 2.0)extender? I seem to recall that the version III extenders were geared towards the version II lenses that were introduced in the last few years (300 2.8II, 400 2.8II, 500 4.0II and the 6004.0 II).

Btw, the 400 5.6 combined with the 1.4 extender does a pretty good job of focusing on the 5dIII. Yes it's f8 wide open, but with good lighting its quite usable.

From several tests I read between the versions II and the versions III, there was very little difference between the 1.4 II and the 1.4 III. However, there was a substantial difference between the 2X II and the 2X III. I would assume this would be valid for any Canon telephoto lens you would use.

nightcat wrote in post #16507525
From several tests I read between the versions II and the versions III, there was very little difference between the 1.4 II and the 1.4 III. However, there was a substantial difference between the 2X II and the 2X III. I would assume this would be valid for any Canon telephoto lens you would use.

This has been my experience as well.

I also went from the 2x classic (mark I) to the mark III and it is a phenomenal improvement. I'll wait 10 more years and go from the 1.4x II to the 1.4x IV and get the optical improvements that are sure to come.

And obviously, by then I'll have won the lottery and will have a 200mm f/2L IS and will walk around with a full-time lens caddy.

I have the 1.4 II and keep thinking I'd like to upgrade to the 1.4 III but I don't use it often and the II gives good results, so, ... I'm still carrying the II.

I, too, recall that the 1.4 III was a bigger improvement (in AF?) with the newer super teles than with the old stuff that I can afford.

I have both and there is not much difference. I'll often have both mounted on different cameras/lenses.

so im looking to pick up the 1.4 II for my 70-200 f4 IS. so for this type of lens there isnt much of a difference at all vs the III? except with the 2.0 version 3 for the bigger lenses?

The mkIII is slightly sharper and I get more accurate metering from mine. The mkII is slightly less that a 1.4x magnification and the mkIII is slightly longer. The mkIII is better built and slightly more rugged.

GMCPhotographics wrote in post #16549921
The mkIII is slightly sharper and I get more accurate metering from mine. The mkII is slightly less that a 1.4x magnification and the mkIII is slightly longer. The mkIII is better built and slightly more rugged.

with what lenses are you comparing this? f4 or some faster ones?

I've had the x1.4 II for several years, and it works really well with 200 2.8, 70-200 2.8 IS and the 300 ƒ4. I'd tried the x2 II and ran away from it really quickly.

Impressed by the x2 III, I bought that and also considered the x1.4 III at the same time.

While there are clear optical benefits to the new x2, I honestly could detect no perceptible improvement in the improved x1.4 - not with my lens set, at any rate.

If you have Mark II lenses (70-200, 300/2.8, etc.), the Mark III 1.4X might make some sense. It's supposedly optimized for the latest lenses.

However with other lenses, all comparisons I've seen have shown little if any difference between the 1.4X II and III. I have just kept using my II and will continue to do so, until and unless I upgrade to Mark II lenses, too. Even then I'll try before I buy.

2X II vs 2X III is a completely different story. But I only use the 2X occasionally and on a couple lenses so have not bothered to upgrade it, either. Again, I might feel differently if I were using Mark II lenses.

I've had a Sigma EX (non DG) 1.4x for years, and have been using it on a recently purchased used 400 f4. It works much better than I expected, http://flic.kr/p/ivvPi​4, and it sounds like you guys are not finding a huge difference between the Canon's 1.4xII and III.

Just wondering if Canon's 1.4xII would be a huge improvement over the Sigma. (I know, loaded question).

nightcat wrote in post #16507525
From several tests I read between the versions II and the versions III, there was very little difference between the 1.4 II and the 1.4 III. However, there was a substantial difference between the 2X II and the 2X III. I would assume this would be valid for any Canon telephoto lens you would use.

I researched this issue about a year ago when I was considering upgrading my 1.4x Mark II to the Mark III version.

Nightcat is right on the optical performance, little improvement on the 1.4x II vs 1.4xIII, but a bigger improvement on 2x II to III. According to Canon Europe, the Mark III versions have a host of improvements that were designed to complement the latest Mark II lenses, particularly the Mark II super telephoto lenses that were introduced at the same time as the Mark III extenders.

http://cpn.canon-europe.com …ses/efmarkiiiex​tenders.do

If you intend to use your 400mm, or acquire the 500/600mm in the future, the Mark III teleconverters will be your best bet. For me, I stuck with my 1.4x Mark II because I was not planning on using any super telephoto lenses.