Re: [photo-3d] Kodaslide II

["Dr. George A. Themelis" <drt-3d@xxxxxxx>]

>I bought
>a few Kodaslide I also and of course they were not any better but they
>were also not that much worse (than the Kodaslide II).

I am surprised to read this... I don't think I have found
anyone to actually see this "chromatic aberration" in the
KII viewer.  IMO, it is not very obvious.  You need to have
a subject like a dark tree in front of snow, to see the blue
edge of the tree.  

Actually, when I studied Rudolf Kingslake's book "Optics
in Photography" (an excellent book worth reading IMO, see
http://home.att.net/~drt-3d/catalog/books/KingslakeReview.htm
for a review) I found an aberration called "Lateral Color".  
>From Kingslake's description ("A particularly sensitive
picture is one showing black tree-trunks agains snow")
I thought that maybe what I see is not chromatic aberration
but "lateral color" aberration.

Still, A LOT of people love this viewer.

The KI viewer with the single element plastic lenses is of
course much worse.

A lot depends on people's expectations.  For example, the
View-Master model D, shows a lot of very obvious chromatic
aberration (just look through the viewer with no reel
inside - the edges are blue) by its lens design (airspaced
single element lenses) but that does not seem to bother
a lot of people.  It was certainly a shock for me... when
I first got this viewer from Reel 3-D, I promptly returned
it, only to change my mind later... You can get used to it!
Same applies for other viewers with similar lens design
(Airequipt, Busch).

In the area of stereoviews, not many people mind the single
element prismatic lenses used in 99.9% of the stereoscopes.
But if you try a achromatic stereoscope, there is a
definite difference.  Once you get used to it, you will
not want to go back to ordinary stereoscopes again.

George Themelis