Viewer lenses

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

I am not sure if I asked Joel's question regarding the white button Realist
viewer.  In short, all the white-button viewers I have seen had
single-element lenses.  I have heard of white-buttons around with
double-element lenses but I am sure that someone must have changed the
lenses because Realist was selling the white button viewer for much less
than the red button.

Regarding the question of difference in optical quality between single and
double-element lenses, a nice article was written by Dr. T in one of
Dalia's Mini-magazines.  The following questions were answered:  "What does
that mean?", "How can I tell?", "Is it worth it?"  Space and time
limitations prevent me from getting into the details.  It's all in past
digests anyway...

"Nothing new under the sun" (Ancient Greek saying), 
"Check past digests" (Dr. T)


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