On Jun 22, 2005, at 8:08 AM, Tom Reese wrote:
I've seen "A"-class extension tubes.
But does anyone make one with the AF mechanism coupled through?
Or would it be better to take a little 1.4xTC and strip the
optical guts out of it?
Kenko makes an AF tube for Pentax. I have one but I've found very
little use for the AF capabilities. In my experience, AF can't
handle the precise focusing requirements in macro work.
It might be useful when coupled with an AF telephoto when you want
to get closer than the lens' minimum focusing distance. I don't
have an AF tele to try it with (yet).
I agree with Tom: AF in an extension tube is mostly inconsequential.
When I'm using tubes, I want a tripod and a fine geared rackmount for
stability and precision focusing.
Godfrey
