Bruce Dayton wrote:
>
> Joe,
>
> I wonder if you would be better of with extension tubes?
If you have the chart that accompanies them, that might be a good idea...!
If not, I don't (offhand) know where to find the data...
In fact, I have a very old set of (3) as-new Asahi M-42 thread 'S3'
extension tubes, numbers I, II and III, that I culled from an old
photo shop's 'goodies' box a long time ago. Nice leather case for
them, etc., but of course, no literature!
I have no idea what S3 refers to.
Maybe when my on-order copy of 'The Pentax Way' shows up, there'll be
something in there...
Maybe Pentax would still have some literature?
keith
> Bruce
>
> Wednesday, September 11, 2002, 9:14:32 PM, you wrote:
>
> WJ> Hi Joe,
>
> WJ> I don't know how to calculate closest distance, but the diopter of the closeup
>lens indicates where "infinity" focus would be in fractions of a meter. In other
>words, the
> WJ> farthest you could focus with a +1 closeup lens is 1 meter, with a +2 it would
>be 1/2 meter and a +3 would be 1/3 meter and so forth. Hope this helps.
>
> WJ> William in Utah.
>
> WJ> 9/11/2002 3:47:42 PM, "Joseph Tainter" <[EMAIL PROTECTED]> wrote:
>
> >>How does one calculate the effect of a close-up lens? (That is, so as to
> >>know what to order by mail.) The Sigma 70-200 f2.8 EX that I picked up
> >>earlier this summer focuses only to six feet. I'd like to pick up a +1
> >>or +2 close-up lens to carry with it. So how does one calculate what the
> >>closest and farthest focusing distances will be with a +1 or +2 lens and
> >>the Sigma at 200 mm.?
> >>
> >>If anyone knows the answer, could you let me know personally as well as
> >>reply to the list? I'm a no-mailer, and Mail-Archive.com seems to be
> >>losing messages these days. My e-mail is:
> >>
> >>[EMAIL PROTECTED]
> >>
> >>Thanks, everyone.
> >>
> >>And thanks, Doug, for getting us no-mailers back on line.
> >>
> >>Joe
> >>
> >>
> >>
