Posted by LEs on November 15, 2000 at 08:20:33:
In Reply to: telephoto lenses posted by Matt S. on November 15, 2000 at 01:10:32:
the benefit of a telephoto lens is that it needs much less bellows to focus on a given point than a lens of normal design of the same focal lenght. This will allow the telephoto to either focus closer or in the case of the 14" tele focus at all.
A pacemaker speed has about 12" of bellows. A normal 10" lens could focus to about 5' where a tele that focuses at infinity with an 8" bellows draw could focus to within 2'.
As to hand holding, it will be a matter of practice, subject distance, subject speed and the angle to the camera the subject is coming or going. The design will not effect the hand holdablitiy other than camera balance--a normal lens will be out farther on the bed.
to start with I'd double the 35mm rule of long lenses-- the inverse of the focal lenght is the slowest speed. In this case the lens is a 250mm I'd practice at 1/250 and 1/500, then drop down and see how much shake you get.