Re: Which Viewer for Well-endowed Man?

[P3D Gabriel Jacob <jacob@xxxxxxxxxxxxxx>]

Bill Davis writes

>Say what?  Maybe the confusion lies in fractured syntax. :--)

Ok ok, yea it's a bit confusing. Let me rephrase that. VM viewer images
are less than 10% smaller than Realist type viewers. ;-)

>O.K., I did this with two identical empty cardboard mounts. To make it a bit
>more accurate I marked 1 mm increments along the edge of the aperture of the
>mount in the KS II.  Carefully following your procedure, I lined up the top
>edges of the respective apertures and took careful note of where the lower
>edge of the View-Master mount crossed my scale. As near as I could tell, it
>crossed at 2.6 to 2.7mm.  Bearing in mind that the aperture height is 23.5
>mm, this calculates (by my math) to between 11.1 and 11.5% difference.
>Although I had expected something closer to 15%, and while this may be not
>really significant to you (you aren't a government worker by any chance, are
>you? :--)), to me it is still a very large difference and was evident even
>without a side-by-side comparison.  

I went back to the drawing board to check out why we got differing results
and I think I know why. I measured as you did but got 1.5mm larger size
with the Realist which translates to 6.4% difference. But after fiddling
around with the viewer trying to reproduce your measurements I realized
that I had the focussing on the Realist viewer farther out. I usually
focus so that the lens are further from the image, which results in
more relaxed viewing IMO. Anyways I focussed to the minimum distance
and then got very similiar results to you. Actually I measured roughly
2.5mm or 10.6%. Close enough to your results for all intensive purposes.

>Now that that is settled (?), can we get back to my original question, which
>was:

So in conclusion I think we can close the door on this and agree on 
the results but disagree on, if the image size difference is really
substantial.

>>Are there any Realist-format viewers available which offer short f.l.
>achromats, >internal illumination, focusing capabilities AND separate lens
>barrels?

>George T., who probably has examined more different 50's-era viewers than
>the two of us combined, did not offer me much hope.  Looks like I'll either
>have to head for the workshop and build my own, or sell something and
>contact Hugo de Wijs.  (Anyone interested in a near-mint Kawasaki 250
>two-stroke triple? )

Well it seems your handy with tools. My recommendation is get the lenses
from Dr.T. This way you can make your dream viewer. For internal 
illumination maybe a pair of 12V 20W miniture halgoen lamps with the
built in reflector might do the job. Then in front of that put a diffuser.
Should work very well except that it will be AC powered, unless you use two
of those motor cycle batteries from your two-stroke Kawasaki. ;-)
Heck that might work so well that it can double as a projector too!

Gabriel


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