On Jun 22, 2005, at 7:59 AM, Steve Jolly wrote:
Collin Brendemuehl 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?
Doesn't a TC alter the lens aperture information provided to the body?
No. Light falls off as you add lens extension by the amount dictated
in the Inverse Square Law, but the aperture doesn't change. A TTL
meter simply reads less light.
Godfrey
