[MF3D.FORUM:37] Re: Apparent image size, MF verus

[Alan Lewis <3-d@xxxxxxxx>]

Bill Glickman wrote:
> 
> Paul
> 
>     It seems this guy Rich supported your cause in the MF forum... so MF
> appears barely larger than 35mm in a viewer, right?
> 
> IF so, we may be on too something, because stipping this up may be the true
> answer to WOW we are looking for, specially using larger formats to shoot
> with...

It is very easy to see how these formats appear compared to each other. 
You put a slide (or just an empty mount) in each viewer you want to
compare.  Hold the right lens of one to your left eye, and the left lens
of the other viewer to your right eye.  You can then toe the viewers to
get the images to superimpose.  It is very apparent the magnification
differences.

Some subjective observations:
1) A Realist image (in a Revere viewer) is MUCH smaller than a MF image
in the SaturnSlide viewer.  Why?  One reason is the lens f.l.  The
Revere (and Realist) viewers do not use a lens that is the same f.l. as
the camera.  The SaturnSlide does.  MF wins in the wow category. 
Perhaps if the Realist viewer used a 35mm f.l. lens the image size
would  have less difference.

2) A full frame 35mm slide in a 50mm lens viewer (orhto) will be approx.
the same width as a MF image in the SaturnSlide (or any MF viewer with
80mm f.l. lenses).  But the height is not as great as a MF image.  So
the MF wins in the WOW category.

You can compare any number of lens f.l. vs. format size this way.

So I think that Pauls' chart on image size is pretty close.  Although I
found that the full frame 35mm image using 50mm lenses (ortho) is about
the same as MF, rather than greater.  Purely subjective though.

As you go to larger film formats you should also match your viewing lens
to the camera lens.  So merely moving to a larger format does not
guarantee a larger image, it depends on what lenses you are using.  As
you move to larger formats than 6x6 (6x9 would be a larger format for
this discussion) you need a different viewer design, and should use a
longer f.l. lens.

One thing I feel is true:  6x6 MF will give you the most WOW factor
using a standard parallel viewing design viewer with a monolith mount. 
This is probably the most convenient design for stereo. 

If you move up to a larger format then you will need to use a Wheatstone
or other base spreading viewer design with individual single mounts.

Of course if you don't care about having an orthoscopic setup then to
get the biggest WOW factor you can merely use much shorter lenses to
increase the magnification.  I've done this with a standard MF viewer so
I end up with 60mm f.l. viewer lenses.  There is no way you will be able
to cover the entire 6x6 slide area with this f.l., but you do get an
immersive feel to the image.

Exactly what is your idea of WOW factor?  It will dictate the method to
use, and what compromises you will have to make.


-- 
Alan Lewis  
mailto:3-d@xxxxxxxx
http://members.home.net/3-d
Serious viewers for Serious viewer's
New stereo viewers & Stereo Wedding Photography