P3D Nimslo Modification

[Project3D@xxxxxxx]

In a message to photo-3D, Lattie Smart wrote:

<< 
 >Well, no $50 Hyponar has manifested itself to me, soooo...
 >I want to try some more close-up and macro shots on my old Nimslo.
 >The out-of-hand solution into tricking the aperature to shut way down
 >is to put a grain-of-wheat bulb over it. I do not think this is too elegant.
 >
 >Has anyone attempted to put some kind of pinhole mask up into the
 >stepped chamber? Would this work - having it BEHIND the lens?
 >Any suggestion how to *properly* go about it?
 
And Tom Deering replied:

<<
> Properly?  I'm not sure about that.  But here's an alternative.  Take the
> thing apart.  Notice that metal assembly the lenses are mounted on?  The
> shutter is that long dark strip behind the lenses-actually two strips.
> When the shutter is tripped, the top one moves right, and the bottom one
> moves left.  The farther they move, the larger the aperture.
 
> If you were to find a way to limit the travel of those two strips, you'd
> have a smaller aperture.   I could think of a couple ways, but it's up to
> you and your skills.
 
> Since the aperture is also the shutter, this might leave you with a
> completely fixed shutter/aperture.   Not so bad if you intend to always use
> a flash.
 
> I have not tried this myself, but have considered doing it to my macro
> Nimslo.  A nice experiment if you like that sort of thing.
 
> Tom >>

Trouble is, the aperture / shutter blades are in the wrong place. I haven't
noticed any increase in depth of field as the aperture is reduced - just an
increase in vignetting as the aperture cuts into the cone of light on it's way
to the film.

For the purposes of close-uppery, it might be possible to introduce a
"waterhouse stop" between the elements of the lens...

It is DEFINITELY possible to adjust the plane of sharp focus by the simple
expedient of screwing the lens assemblies into the mounting barrels. You might
like to set the middle two lenses to, say, 3 feet whilst having the outer pair
at 15 feet. Select the pair that are sharpest for each shot...

The Nimslo is certainly a camera that's worth experimenting with!

Bob Aldridge


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