This is to compare the MKIV (1.3) with a 1.4X and a 1DX (FF) with a 2X extender: The focus points were right on target. I'm not happy with the 2XII extender with the Version One 300mm f/2.8 lens. These shots below were taken 1 year apart, but if you look at the 2 uncropped versions you will see that they were taken at the exact same location, by noticing the green buoy and the light pole on the right. Believe it or not these were both taken 1 year apart minus 3 days and 45 minutes. I guess I'm a creature of habit. They were both taken with Canons drop-in CPL and a Monopod.
These shots are 95% SOOC. The pole was a little tilted and if I straighten it too much, the water horizon looks tilted. I will also mention that it was a little windy with the 1DX shots, however I increased the SS to 1/2000sec which I thought should have been enough, plus I believe I had IS on to assist. If I had to guess, knowing my habits I would guess that I had IS off for the MKIV shots. I wish Apple Aperture could check this. Does DPP report IS, I never use that?
I would ignore the differences in exposure, saturation and ISO and just focus on the IQ.
MKIV 300mm f/2.8L IS +1.4X @ 546mm Uncropped f/6.3 1/1000sec ISO 400
CQ0H3194 by RL One Photography, on Flickr
MKIV 300mm f/2.8L IS +1.4X @ 546mm Cropped
CQ0H3194 - Version 2 by RL One Photography, on Flickr
1DX 300mm f/2.8L IS +2X @600mm Uncropped f/6.3 1/2000sec ISO 1000
BP1Q2166 by RL One Photography, on Flickr
1DX 300mm f/2.8L IS +2X @600mm Cropped
BP1Q2166 - Version 2 by RL One Photography, on Flickr
I will try to do some more controlled testing. I haven't done any AFMA on either camera. Maybe the 1DX needs some lovin'.
Thoughts?
Rich