First question: Are these 62mm? I'm assuming so since the 70-300 is, but
want to be sure.
Which one is probably the best candidate? Between the 14A and 201, I'm
leaning towards the 14A, as I'm concerned that not only would 2 stops of
loss be killer on 5.6 (yes, I know none of them will AF on this lens at
300), but a focal length of 600 will require a shutter speed > 500ms (for a
hand-held attempt), for the equivalent loss of a 3rd stop (double the speed
requirement). So 5.6 at 2000ms would now be 11 at 1000ms in the best-case
scenario. Doesn't seem very likely.
The 14A would cause only 1 stop of light loss, and the focal length increase
would cause a minimal speed penalty such that 5.6 at 500ms (for a 300 focal
length) would now be 8 at 500ms (for a 420 focal length).
I saw someone mention wanting a 16A. Does this exist? Is it optically as
good as the 1.4x? That would bring a 300 to 480 and would cause only about
1 1/3 stops, so a 5.6 would be around an f/9, but the shutter speed would
still stay at 500ms (480 focal length). Since AF is gone, it seems like
that would certainly be worth considering for this lens if the optical
quality is same or similar.
So what I'm asking is this: Is the 201 not worth considering if I'm only
going to get one TC? Does the 16A exist and is it as favorable a candidate
as the 14A? Or is the 14A the best candidate in this case?
Ross
