Thanks Moose and Chuck for the clarification. I learn something every
day on the list.
Alan Wood site lists early versions as single element which is
probably why I recalled it that way. I would bet the $94.00 one for
the IS-3
was 2 element.
http://www.alanwood.net/photography/olympus/close-up-lenses.html
Must be quite difficult to preserve IQ with 6 diopters. On an 80mm
lens that is about a mag of 1:2 at infinity. Not sure how the mag gets
to 2:1
on the autotube, but it clearly doesn't focus at infinity.
Mike
BTW, I think the Nikon 2 element guys were taken off the market a
couple years ago, though the pricey Canyon ones are still available
new.
Stephen Gandy said the close up diopter included with the CV SL11
90mm is single element. Go figure.
> I didn't realize the FL of the screw -in diopter. I don't think it
is a 2
> element apo design. I don't think Dean was thrilled with the results.
Two element. <http://www.angelfire.com/ca/erker/closeups.html>
As it says, though, I believe 2 element is acro, not apo. Not even sure
if such
designations are meaningful in context,
as the lenses they are put in front of are usually not apochromatic.
--
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