"Bill D. Casselberry" wrote:
> > Besides using 200mm of extension with a 200mm lens already
> > capable of 1:1 reproduction ratio seems a little excessive.
>
> I agree - it will become physically unmanagable at some
> point. I might suggest that you use a 50mm macro w/ your
> 200mm of tubes rather than the 200 - should give you
> somewhere around 4:1 mag ratio which would be an actual
> field of 1/4 by 3/8 inches.
OK, let's look at it from this perspective. First, I don't
have a 50mm macro that I can use for this project. I do have
the A100/2.8 and the A*200/4.0 macro lenses.
The item I want to photograph is about 11mm in diameter. I
would like to fill as much of the frame with it as possible,
i.e. about 2X magnification. I haven't been able to do that
with just the lens alone or the lens with 68mm worth of tubes,
that's why thoughts of greater extension are running through
my mind.
I can manage the additional tube length with no problem, so
that's not a consideration. What concerns me is the quality
of the image. If the image were life size on the film, and I
made a 16x20 print, would the image on the print be of higher
quality than if I used longer extension tubes, got something
closer to 2X life size on the neg and then made a 16x20 print,
with the final image on the print being the same size in both
cases, almost 16" in diameter?
--
Shel Belinkoff
mailto:[EMAIL PROTECTED]
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