Just started testing with FoCal and my d800E
Using the newer version of the 200-400mm I was surprised that there was only a very slight drop in sharpness values using the teleconvertors. VR was off. I did test at an iso of 400, as I never have enough light to shoot with TC's at 100iso.
Using the aperture sharpening test I got the following values:
200mm- 2800 @4.
400mm- 2900 @f5
550mm- 2500 @f8 using the 1.4x
650mm- 2800 @7.1 using the 1.7x
800mm0 2100 @ f8 using the 2.0
I could not get it to complete the focus testing on the 2.0- kept locking up. At least in testing the 1.4 and 1.7 look like winners here- need to go shoot more and find out. I was always reluctant to use these on the 200-400.
Dang, it is going to take a lot of time to adjust lenses and Tc's for 3 cameras.
Gary

>I just finished all of my 200-400mm f/4 testing with the
>D800E.
>
>I got the same results that I got with the D800 except higher
>QoF values across the board. VR made little difference at
>400mm. When I put the 1.4x TC on (bringing the focal length up
>to 550mm), the QoF values dropped dramatically. Turing on VR
>brought the QoF values back up, but they were still 25% lower
>than shooting at 400mm with no TC.
>
>Conclusions are the same as with the D800 and 200-400mm f/4:
>- Use the TC only when desperate
>- Always turn VR on when the TC is installed

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