DIY: velvet or velour inside SCT tube

"Steve Little" wrote in message ...
wrote in message
...

There's an old saying: "If it ain't broke don't fix it." :-)

If the inside wall of the baffle tube isn't smooth (e.g., it's ribbed)
then
there's not much else you'll be able to do because it _is_ baffled (though
how well is another matter :-)

If the inside wall is smooth (as it was in my Apex 90), then there is
benefit gained by flocking it (as I did). Here's how I did it using
ProtoStar flocking paper.
[...]

Did it work, or could you tell the difference?

Yes, as I wrote: "benefit gained". :-)

The Apex 90 has an unbaffled baffle tube (oxymoron? :-) and flaring was a real
problem. Shining a flashlight into the front revealed the "leakage" paths into
the baffle tube (from around the secondary on the meniscus lens). Not only did
I flock the inside of the baffle tube I also flocked the entirety of the inside
of the OTA and the edges of the secondary.

The flocking definitely reduced the flaring but did not eliminate it entirely;
it's no longer as objectionable as in the "stock" condition. The original
flaring was a condition where the presense of an object NOT in the field of
view could be determined by "random" scattered light, readily noticeable with
the Moon and bright objects (Jupiter, Mars, Sirius, etc.)

At acute angles (less than, say, 10 degrees) even flocking paper will reflect.
Where it really shines (no pun :-) is inside the OTA opposite the focuser of a
Newt (though it'd be better to line the entirety of the inside esp. if the Newt
is unbaffled (as many are)).