RBT Zooms/ 50's fixed focal comparision

[P3D <JGoldenRRP@xxxxxxx>]

Bob H. comments:
>What bothers me about the RBT and melding, is that it seems to me  they just
grab two lenses marked 50mm or whatever. Two zooms are an awful thought as
they surely don't agree on a given marked postion. All the early '50s stereos
had matched focal lengths as did the preceeding generation cameras (short of
box stereos). This was not done by picking the label but by matching on an
optical bench or similar means.

Greg Wageman replies
>>Bob, If I remember rightly, the literature advertises "matched, coupled
lenses". I would presume that means more than simply picking two lenses of
the same type.  Also, the coupling arrangement could allow for some
fine-tuning of any differences.  Jon Golden might like to jump in and comment
here...


Jon Golden....
Bob.....RBT also puts those zooms on an optical bench,  matches and aligns
two lenses to the camera's bayonets.....they are NOT just "thrown
together"....as you might assume.   But I do agree that matching a pair of
zooms is a tough job....but RBT does it well....in fact the X2 that Greg will
receive is their most popular model for the zoom feature, twelve of these
cameras are beinmg deliverd in late October.....and that does not happen by
creating a camera that has misaligned and inferior optics.
Bob.....point well made,  matching zooms is something to wonder about....but
comparing the matched fixed focal length  cameras of the 50's to a pair of
zooms on an RBT is apples and oranges.  Two different animals with two
different purposes.
 Example: If I am sitting at Fenway Park (where the Red Sox play), about 25
rows back to the side , behind home plate....with my Realist......I can get a
nice 3-D of the game....but the 3-D  will be made up of heads and backs in
the rows in front of me....and the players on the filed will be tiny ants out
there, far away......thats fixed focal length for you.  With the X2 and
zooms.....I can zoom in and grab those players....and might I add that the
RBT X2 performs very well in the zoom-in position.....and those lenses better
be well aligned for accurate vertical and zoom tolerance. 
Sharp, aligned images are what we strive for.....perhaps a more fair
comparison would be to look at a matched pair of fixed focal length lenses on
an RBT X2... in fact....to cover that base....Greg....as well as a few others
on the next order arriving from RBT....ordered sets of fixed focal length
lenses.

If I can clarify anything further, fell free to contact me.
Thanks Jon Golden RBT USA


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