[MF3D.FORUM:1192] Re: Newbie seeks advice

[Paul Talbot <ptww@xxxxxxxxx>]

Linda Nygren wrote:
> 
> Hi, folks. Many of you may know me from the p3d list, but I am just
> about to try a little medium format for the first time

Delighted to hear it!  :-)

> I have ordered some 120 film from B&H which should arrive shortly, and I
> have put the two cameras on a bar on my tripod. The interlens spacing
> seems to be about 84mm at the closest in this arrangement. The lenses
> are 80mm/3.5. The basic shutter mechanics and focusing seem to work OK.
> The images seem to be reversed

Yes, a TLR (twin lens reflex) typically has a "waist level" finder with
a mirror image of the scene on the ground glass.

> and pseudostereo if parallel freeviewed in the viewfinders?

Pseudostereo when parallel freeviewed?  I can't even imagine parallel
freeviewing something wth 84mm center spacing!  I have no experience
with this, and I'm incapable of the geometric gymnastics required to
figure out whether that makes sense.  I just tried freeviewing some
uncut film in a mirror, attempting to simulate what you are seeing
in the camera viewers.  When viewed in reverse (mirror image) it does
appear pseudo when parallel viewed.  Does that make sense, folks?

> I am not sure how to determine stereo base in this format compared to
> 35mm photography. I believe that the larger film format makes a
> difference so that you can't just extrapolate from the focal length of
> the lenses, right? Do viewer optics also play a role?

Yes, but you can still apply the advice that on-film deviation should
be limited to 1/30 of the viewing distance.  The viewing distance is
roughly the same as the FL of the viewer lenses.  For ortho conditions
that would be 80mm; 1/30 of 80 is 2-2/3mm.  For scenes that include
infinity, it conveniently works out that the familiar 1/30 guideline
used in 35mm works just as effectively for medium format.

As Bill pointed out, 1/30 is still a good place to start out for many
scenes that don't fall within the normal constraints suggested for
using the 1/30 guideline.

> I have never used
> 120 film or this type of camera, so any advice would be appreciated.

Don't forget to advance the film!  Double exposures are common to MF
newbies.  Establish a routine like c0ck*, shoot, advance, and stick to
it.  "Film is cheap" doesn't apply in MF to quite the same extent it
does in 35mm.  

*modified spelling attempting to circumvent filters on some subscribers'
mail systems!

Watch out for depth of field.  Shooting stopped down is even more of
a requirement in MF than in 35mm.

> I do have a tattered copy of the camera instructions here to peruse also.
> (My motto: When all else fails, read the instructions.)

I thought that was a "guy" thing!  ;-)

> I also do not have a viewer or mounts yet. I know there are a few good
> options for viewers out there, and it sounds like RMM is the best
> (only?) source for slide mounts?

Quentin Burke also has MF3D mounts.  Greg Erker has posted some
comparison comments.  Two of his posts in the archives may be helpful:
http://www.pauck.de/archive/mailinglist/mf3d/mhonarc/msg03448.html
http://www.pauck.de/archive/mailinglist/mf3d/mhonarc/msg01955.html

There are also some mounts made in Germany by Michel Lembke:
http://kunst.freepage.de/cgi-bin/feets/freepage_ext/41030x030A/rewrite/stereoskopie/6x13seite.html
and a metal mount made in Japan:
http://www.ny.airnet.ne.jp/toaphoto/00may/sindex/mount/html/mz66.html

Hope this helps.

Paul Talbot