Canon Extenders - II to III differences?

[slb_000]

I'm considering purchasing one of the Canon 1.4X or 2X extenders, for use primarily with a 5D Mk2 / 70-200F4L  camera and lens combination, and wondered if anyone can comment from experience on the image quality you can expect to get from them, particularly how big a difference there is between the II and III versions of them. 

(I am already aware that the 2X will loose autofocus in that combination).

Thanks,

Simon

[stever]

i bought a 70-200 f4 about a year ago after testing 2 copies in comparison to the 70-300L and decided that the 1.4iii was enough better than my old ii to make replacement worthwhile.  the 70-200 with 1.4iii had just slightly less resolution wide open at the long end than the 70-300 but was the same or better at the short end.  in addition to noticeably better resolution without the extender, the 70-200 is so much more pleasant to use than the 70-300 that the choice wasn't too difficult.  testing 2 copies of each lens and the extender i found no significant IQ differences

the 70-200+1.4iii with the 5D2 is about the same as the 100-400 and both will make very satisfactory 17x25 prints.  my guess is that the 70-200+2iii will be fine for 13x19 prints and marginal for larger sizes.  Art Morris loves the 70-200 f2.8ii+2iii.  the-digital-picture.com has comparisons of the 1.4xii and 2xii vs iii on several lenses including the 70-200 s

i recently used the 70-200+1.4iii and 500D closeup on my 7D for some macro shots of flowers and bees - haven't printed yet, but the pixels look pretty good.  the 70-200 with 500D (58mm with step-down ring is fine at macro apertures) gives me a reasonable travel macro capability for unexpected opportunities.

[marcmccalmont]

Biggest difference I noted on the 2x was the III is a bit sharper in the corners, since wildlife subjects are centered probably not worth the upgrade but for landscapes where corners are important it would be worth it.
Marc

[torger]

Look at the digital picture test charts, it shows performance for both 1.4x II, 1.4x III, 2.0x II and 2.0x III for many lenses, here's a comparison with 2x II and III on 70-200/4:

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=104&Camera=453&Sample=0&FLI=6&API=2&LensComp=104&CameraComp=453&SampleComp=0&FLIComp=8&APIComp=0

The version III provide better sharpness, better contrast (also in the center of the image, relevant for wildlife) and less chromatic abberations in the corners, more differences on the 2x than on the 1.4x. I certainly think it is worth getting a III if buying new, but if you already have a II you may not think it is worth upgrading.

[Hans Kruse]

I'm considering purchasing one of the Canon 1.4X or 2X extenders, for use primarily with a 5D Mk2 / 70-200F4L  camera and lens combination, and wondered if anyone can comment from experience on the image quality you can expect to get from them, particularly how big a difference there is between the II and III versions of them.  

I use the 1.4x TC III with my Canon 70-200 f/2.8L IS II and Canon 500 f/4L IS with Canon 1Ds mkIII and for both the TC III is really worth getting over the old model which I have sold. It's not only sharper in the corners but over all the image area with better contrast and details. I have a 2x TC II and tried the 2x TC III on my 500mm lens but I would not invest the money in this extender. I have made a few test shots on the 70-200 f/2.8L IS II with the 2x TC II. They are surprisingly sharp and certainly better than upsampling from 1.4x TC III which I have tested too.

The problem I found with the 2X TC (both II and III) with my 500mm lens is the bokeh which does not have the butter smooth appeal as without the TC at all. With the 1.4x TC the bokeh can suffer sometimes especially for wild life with shiny straw or branches behind a bird or animal. I have not done an extensive test per se of the bokeh between the different TC's and on different lenses, I have just noticed browsing through the images I have and taken with the different TC's that the 1.4x TC III stands out and the 2X TC's are nice to have, but really not good enough for critical work in most cases. As mentioned it is the bokeh that really suffers with the 2x TC's more than sharpness and details. Contrast also suffers. The 1.4x TC III can give the crispy look (almost) that you get from a naked lens like the 70-200 f/2.8L IS II (and the Canon 70-200 f/4L IS) and the Canon 500 f/4L IS even fully open.

[Petrus]

I have both in II versions and find 2X just about useless (loss of both resolution and autofocus) while 1.4X just extends the focal length like it should. I have used 70-200 f:2.8, 300 f:2.8 and 400 f:4 with them.

[Hans Kruse]

You only loose AF on non-1D cameras if the the base lens is higher than f/2.8 since the 2x TC loose two stops. So a 70-200 f/2.8 becomes 140-400 f/5.6 with the 2X TC attached. On the 1D-series cameras (except the 1DX) AF still works for f/4 lenses (f/8 with the 2X TC) but only for the middle AF point.

[fike]

I hate extenders. 

Don't get me wrong. I use them, but I hate them.  When you get to longer focal lengths, everything is conspiring against quality: haze, vibration, shallow depth of field, lens quality.  The extenders add another negative to the equation.   A few years ago, I did some extensive experimenting with my VII extender on my 100-400 and found no usable increase in resolution.  I am still using my 1.4x II, but mostly because I can't imagine that the VIII would be so much better that it would change my general disdain for extenders...again, the extenders that I use somewhat frequently on my 400 f/4 DO.

[Preeb]

I've been using the 70-200 f4 IS with the 1.4 II extender for about a year now on a 60D and I find it to be an extremely sharp combination.  Even while I still had my T1i I was able to get good shots of birds in flight, and that's even easier with the improved AF on the 60D.  I find that I can crop closeups to near macro magnification with marvelous detail.  I really like this lens combo on my crop body.