In article <33297252.1E07@foto.no>, nikon@foto.no says...
[...]
>The 300 f/2's came with a special-designed 1.4 converter (TC-14C). This
>may also be used on other Nikors, perhaps the best results are in
>combinations with either the 200 f/2,400/3.5 or the old 600 f/4 Nikkors.
>Be aware that this converter (contrary to a widely held view) is
>unsuitable for nearly all other lenses. This is because it exhibits very
>strong off-axis colour aberration with most lenses excepting those
>mentioned before and of course, the 300 f/2 itself. On axis, TC-14C
>gives terrific results with a number of lenses but this cannot
>compensate for the off-axis fringing found with so many of lens/TC-14C
>combos.

Hmmm..., I have yet to see this... I find edge/corner performance
at wide apertures better than the TC14/14B on the 400mm f3.5,
and also on the MF 300mm f2.8 and the 80-200mm f2.8 AF. I have
not compared them on the 300mm f4AF, but the C is first-rate
on that lens also. On the 135mm f2.8, there is some field curvature,
but otherwise excellent sharpness. On the 500mm f8 (older-style),
the 14/14B does perform better than the C (and quite well!). I
have also used the C with a tube in front in macro work, with
fine results.
Hope This Helps