Nishika Macro

[P3D <LeRoyDDD@xxxxxxx>]

John Vala discusses modifying a Nishika for stereomacro(extreme closeup)
work:

"...I figure I need a 538mm lens
(500mm closest choice) about 10mm away from the 34mm lens and 
this will give me the the s of 34mm that I can't change and allows
me to focus on an object which is about 2.5 feet away.

   Now, given this, I figure I can use three different pairs of 
the Nishika lenses to capture fairly accurate macro images.  
If I use lenses 1 and 3, I get a lens spacing of 37mm which I 
figure is just right for an object at 2.5 feet with infinity 
in the background.  I can use lenses 1 and 2 for objcts as 
close as 18 inches (if the depth of field of the lens at 
f/22 will let me), and use lenses 1 and 4 for an object as 
far as 4 feet away.

...how do you figure these will look in the half 
frame format of the Nishika?  I'm used to viewing full frame 
from my slidebar 35mm camera(s)."


     Following is an off list message I sent regarding lenticular closeups
for the Nimslo which somewhat applies:

"I don't know nothing 'bout optics Miss Scarlett!"
     That said, I just got the largest diameter lens available in the focal
length at which I wanted to take pictures.
     A 12in focal length will give an image width of about six inches, 30in
about 15in width and so on.
     The resolution of 3x5 prints is so poor that merely measuring from the
front of the camera to the subject[at the distance of the focal length of the
added lens] is ok for focus, but you might want to do tests w/slide film for
DOF if you want to do enlargements; also to make "feelers" to assure accurate
framing and exposure using flash.
     Bright sun on the subject gives ok DOF with the camera's sensor, but if
light is less than that, I'd use flash while shining a bright penlight into
the sensor... about f22, I think.
     In general, it's wise to limit the background as much as possible since
total depth due to crossing axes increases rapidly and DOF runs out pretty
quickly."

     Additional thoughts for John...

     Most folk think including actual infinity with a subject at 2.5 feet
will give way too much depth.
     The "one in thirty" rule can be jettisoned for this kind of work... it
all depends on your(and your audience's) toleration for the amount of depth
in the image... the closer you get, in general, the less depth you'll want in
your scene... and the less DOF you have, too.

     Using a single supplementary spanning both taking lenses will preserve
image width, which is already narrow.
     If you want to use a single supplementary each on lens two and three,
hack out the septum between image one and two and also three and four to get
better field coverage without keystoning. This might let you get really
close.

LeRoy Barco
LeRoyDDD@xxxxxxx


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