I think the image circle is "large." The bellows lenses were being
designed for use with a tilt-shift bellows that never made it to market.
The image circle also increases of course as the magnification
increases. I recall Walt used the Z. 135 f4 macro in some type of LF
rig. I have yet to see any vignetting with the 38mm, 80 f4 or 135 with
10 deg of tilt on the Mirex adapter with the lenses on the autotube
though stopped down at least one stop. The Alan Wood site says the 80
f4 was optimized at 1:1. I have never seen any MTF data though it
likely exists somewhere. It appears to be perfectly symetrical double
gaussian? design. I recall CH's very nice flower shots with it wide
open.
Probably doesn't help a wit.
Mike
I have also produced some very high magnification with reversed high-
quality
lenses - Interestingly enough (and before I was the recipient of a
gift 20/3.5) the highest
resolution/magnification I've personally gotten was a reversed Zuiko
24/2.0 stuck to
my 135/3.5 :-) Quite extreme. Although few lenses are flat-fielded
enough to look good into the corners,
unlike the 20/3.5 which is perfect even at f/3.5 right into the
corner. (because it also projects an image
circle large enough to cover 4x5in film, so "corner" of the 35mm frame
is still pretty close to the centre
of the image.)
Did you guys know the 20/3.5 can cover 4x5in film at its optimum
working magnification? Also, my pet project
sometime will be to find a way to stick it onto my RB67 - 6x7cm at 12x
magnification, with vibration-less leaf
shutter sounds like heaven to me, assuming I can focus the thing.
Anyway, any reversed lens is going to absolutely suck compared to the
80/4.0 at 1:1 magnification,
even though they will do better at very high magnification.
So... as per my earlier request - does anybody have some real
resolution / MTF figures for the 80/4.0? And, while
they are at it, size of image circle? I don't think it'll be as
extreme as the 20mm, but I wonder if it'll cover
6x7cm?
On 01 Oct 2009, at 2:30 PM, Wayne Harridge wrote:
> Just for an interesting comparison:
>
> Same set up substituting a reversed Minolta C.E.ROKKOR-X 30/2.8
> @f5.6 for
> the Zuiko 80/4.
>
--
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