"Rank Amateur" wrote in message
link.net...
Last night I attended a star party here in Central Texas. The seeing was
unusually good for this area, and, among other things, I observed the
Trapezium through three SCT's -- an old orange-tube C8, a brand new
one-arm
C8, and a recent-vintage Meade 10". Through the orange tube, the
Trapezium
stars were beautiful, sharp points and the E and F stars easy to see.
Through the other two scopes, the Trapezium stars appeared a bit "dull"
and
lackluster, and the E and F stars were barely perceptible.

Was the orange tube just an unusually good SCT, or maybe it was just
better
collimated? The eyepieces and diagonals were comparable on the two C8's,
and the Meade had high-dollar TeleVue eyepieces and diagonal.

I tell you, after observing through the orange tube, I am convinced that
SCT's can give excellent views.


My guess is that the orange tube was in proper collimation and performing
normally, while the other two were out of collimation. I find it amazing
that too many SCT owners don't know the first thing about collimation. Go
to any star party and you will find many SCTs which are out of proper
collimation. At this moment, I own 3 SCTs and I check collimation before
each use.

While the SCT design pays some in optical performance for it's outstanding
portability, it will still provide excellent views. What the SCT loses in
optical performance, it will more than make up in easy to carry, easy to set
up, easy to transport and easy to buy aperture.

Al