Pauls0627@xxxxxxx wrote:
> In a message dated 9/17/98 3:09:59 AM Eastern Daylight Time, gma@xxxxxxxxxx
> writes:
>
> << Rule of thumb: Length of tube for 1:1 = half the focal length of the
> lens, if the lens goes to 1:2 by itself. Eg for the 50 macros, 25 tube
> does it. For the 90, 45 mm tube needed. (or 25+14+7) >>
>
> Correct me if I'm wrong, but I believe that for 1:1 the total extension must
> equal the focal length. So for the 50mm macros, which have 25mm of extension
> with the helicoid, you need to add 25mm extension to get 1:1. Using George's
> other example, then the 90 must have 45mm of helicoid travel (I don't know for
> sure if it does or not).
>
> Paul Schings
> Coventry, RI
>
Paul;
It does. It goes to 1:2 on it's own.
george
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|