What's the Difference: 1.4X EF Extender 2 Vs. 3

[RussRoc]

Can anyone tell me what changed on the version 3 (versis version 2) for the Canon Extenders?

Is there some advantage to shooting the 3 Vs the 2?

[neuroanatomist]

One big difference is the AF circuitry, which was optimized to work with the newer MkII supertele lenses to provide faster and more precise AF when using the extender (AF performance with other lenses is the same as the MkII extenders). 

According to Bryan at TDP, the 1.4xIII has less barrel distortion and noticeably less CA.  The 2xIII is slightly sharper in the mid frame and corners, and has slight barrel distortion (whereas the MkII had slight pincushion distortion - which is generally less noticeable than barrel).

Physically, the 2xIII has two more elements and is 22% heavier; the 1.4xIII also has two more elements (grouped differently, so one less group), but the weight is pretty much the same.  The MkIII versions have the fluorine coating on the exposed elements which makes them easier to clean.  Also, the MkIII extenders have the 'new' paint color which matches the MkII superteles, if that sort of thing matters to you...

[Mt Spokane Photography]

They are a tiny bit sharper, probably not worth upgrading unless you are super critical, or, of course, if you have one of the new super-teles at $10K +, why not.

[tron]

They are a tiny bit sharper, probably not worth upgrading unless you are super critical, or, of course, if you have one of the new super-teles at $10K +, why not.

Have you verified that? I mean there  are tests at TDP some of which show the III just a little better but some show them equal. I was thinking about version II telephotos in which case I guess everyone would say go for version III but come on have you made comparison tests? Even TDP has tests only with version III.

I am writing this because I just got 500 II, paid a lot and if the difference is so small as negligible I prefer to not spend more money for now (I have version II teleconverters).

In addition, EF1.4X II is excellent. If I were to update I would update EF2X II.

On the other hand I happily stacked them in a  non-critical case like a moon photo.
 
This cannot be done with version III...

[neuroanatomist]

I just got 500 II, paid a lot and if the difference is so small as negligible I prefer to not spend more money for now (I have version II teleconverters).

If you only shoot the moon and other things which move slowly or not at all, there's not a substantial benefit to upgrading.  But if your subjects move, the improved autofocus performance with the MkIII extenders is reason to upgrade, if not for the IQ benefit.

[tron]

I just got 500 II, paid a lot and if the difference is so small as negligible I prefer to not spend more money for now (I have version II teleconverters).

If you only shoot the moon and other things which move slowly or not at all, there's not a substantial benefit to upgrading.  But if your subjects move, the improved autofocus performance with the MkIII extenders is reason to upgrade, if not for the IQ benefit.

I have read that autofocus speed decreases by 50% with EF1.4X III and by 75% with EF2X III.
Are there any measurements with version II ?

[neuroanatomist]

IIRC, Canon stated improved precision with the MkIII extenders and MkII supertele lenses, not increased speed (although the latter may also be true due to better algorithms in the extender chips, not sure).

[Harv]

I owned both 1.4x and 2x extenders V.II for use on my 500/4 V.1 and 300/2.8 V.1 and when they V.III extenders were released, I upgraded both.

I didn't really see any  noticeable difference with the new 1.4x (perhaps just a tad in the corners) but I did find a noticeable improvement with the 2x on both lenses.  Across the entire frame.  I rarely used the V.II 2x because I was never really happy with the results.  Now I use the V.III 2x all the time and am very happy with the IQ it delivers with both my 1D Mark IV and my 5D Mark III bodies.

If I had it to do again, I would not bother to upgrade the 1.4x extender for my use.

Just my personal experience, for what it's worth.

[tron]

I owned both 1.4x and 2x extenders V.II for use on my 500/4 V.1 and 300/2.8 V.1 and when they V.III extenders were released, I upgraded both.

I didn't really see any  noticeable difference with the new 1.4x (perhaps just a tad in the corners) but I did find a noticeable improvement with the 2x on both lenses.  Across the entire frame.  I rarely used the V.II 2x because I was never really happy with the results.  Now I use the V.III 2x all the time and am very happy with the IQ it delivers with both my 1D Mark IV and my 5D Mark III bodies.

If I had it to do again, I would not bother to upgrade the 1.4x extender for my use.

Just my personal experience, for what it's worth.

It is worth. I have always been satisfied with my EF1.4X II but until recently the only use of EF2X II that was really worth was back in 2006 when I had used my 300mm f/4L (non-IS) with that 2X teleconverter and photographed the total eclipse.
An improved 2x teleconverter is always useful.

[tron]

I have some purely sentimental reasons to not try to get rid of my II teleconverters though.
The version III cannot be used with any analog bodies except the 1V. The best analog bodies I have are EOS1n.
That and the fact that I will not be able to stack them (but that is mostly for fun).
However 2XIII tempts me. (Maybe next year)

[Jack Douglas]

I'm pretty happy with my 2X III when used with the 300 F2.8 II.

6D  300 X2  1600th  F10  ISO 1600  This is a pretty heavy crop shot at minimum focus distance which appears to be one of the advantages of the 2X.  I have no complaints about focus speed but am not using it for BIF.

Jack

[GMCPhotographics]

I've had the mkII and mkIII 1.4x TC together. I sold the mkII last year (I needed two at the time) and I found the mkIII to be a little better in every regard. Slightly sharper and slightly better with it's AF. Less Vignetting and less CA. But those differences didn't make huge difference in the final pictures.
I'm currently using the mkII 2x TC. I've used the mkIII version and it looks like a greater improvement over the mkII - mkIII 1.4x converters. There seems to be slightly more Image Quality improvements. Then again, not everyone needs a 2x TC!

[johnf3f]

I owned both 1.4x and 2x extenders V.II for use on my 500/4 V.1 and 300/2.8 V.1 and when they V.III extenders were released, I upgraded both.

I didn't really see any  noticeable difference with the new 1.4x (perhaps just a tad in the corners) but I did find a noticeable improvement with the 2x on both lenses.  Across the entire frame.  I rarely used the V.II 2x because I was never really happy with the results.  Now I use the V.III 2x all the time and am very happy with the IQ it delivers with both my 1D Mark IV and my 5D Mark III bodies.

If I had it to do again, I would not bother to upgrade the 1.4x extender for my use.

Just my personal experience, for what it's worth.

That matches my findings on my 1D4. The 1.4 Mk2 or Mk3 seems to make little difference on my (Mk1) lenses but the 2 x Mk3 really shines IMO. My 2 x Mk2 was really only usable on my 300 F2.8, the Mk3 produces very good results on the 300 F2.8, pretty good on the 300 F4 IS and 600 F4 IS and surprisingly useable images on my 800 F5.6 IS (MF or Live View).
In my case the 2 x Mk2 was a waste of money, whereas the slight improvement that the Mk3 gives is the difference between print and delete - a small improvement in IQ that makes all the difference!

[tron]

So it seems all of you who had compared EF2X II and III agree that 2X III has better IQ than version II. Next year I will give it a serious thought.
Thanks for the information.

[alexanderferdinand]

@ Jack Douglas: awesome picture!!