I own the DO as well as a 500 f4, and I own a 1.4x II as well as both a 1.4x III & 2x III. While I found a significant improvement on my 500 (Version 1) with both III converters, I could not see any difference on the DO with the III converters so I hung onto by 1.4x II to use with it.
Here\'s a shot made just yesterday with the DO and a Mark IV.
Oct 09, 2013 at 10:34 PM
Previous versions of Chris B.'s message #11854418 « 400 f/4 DO USM lens »
