P3D Re: RE: Close Focussing Realist

[fj834@xxxxxxxxxxxxxxxxxxxxx (Dr. George A. Themelis)]

>Anyone actually done this?  Anyone have any idea how close you can actually
>get a Realist to focus?  Any downside to this?

The original report by Bruce Mills said that the next round of the wheel
will let you focus between 20 and 14 inches.  So we have:

  Round             Max Focusing     Min Focusing
---------------     ------------   ----------------
First (normal)        INFINITY       2 1/2 ft (30")
Second                  20"              14"

Not sure why there will be a gap between first and second round (30" and
20") since the movement of the focusing knob is continuous.  Bruce
suggested not trying to advance in the second round because the increased
pressure on the film plane might damage the film. Instead, go back to the
first round and advance.  He mentioned replacing the screw with something
that allows him to go back and forth without having to remove the screw.

Care should be excercised in keeping track in what round you are as
there is no indication in the camera.... thinking that you are in the
first round while you are actually in the second (or the other way 
around) is a fine way to ruin a good part of the film!

While I have not tried that, I see it as an alternative to using close
up lenses, taking advantage of the Realist's wide focusing plane movement.
If I were going to try it, I would first check the focusing distances with
a ground glass and mark the second round focusing distances with a fine
marker right on the focusing wheel.

>(And, given a close-focus scenario, you'd obviously have to determine in
>advance your desired base, block one lens, shoot, slide the camera to
>achieve base, block the other lens, shoot, advance in order to get a good
>pair.)

Not that obvious to me... One advantage of using the Realist (instead of
an SLR camera in a slide bar) is that you can shoot moving objects.  And
you can do that while still using the rangefinder and centrally located
viewfinder. (I would first have to check the accuracy of the rangefinder
vs. the second round markings on the wheel.)

Clearly, the large stereo base (70 mm) of the Realist will put a
limit in what you can shoot like that.  (But still better than nothing,
and for some people better than carrying extra camera bodies, lenses and 
slide bars.)  

Also, you will need to use close-up mounts (half frame most probably) to 
mount the chips, due to the loss of image area (see discussions in
tech-3d).  (I guess I would be much better using a 7p Realist in that 
respect...)

Finally, the image quality of the (optimized for infinity) lens is
something to be investigated too.  Small apertures and use of flash
might be required as with most macro cameras.

George Themelis


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