You may want to blacken the tube if it's brass as this will end up with a thinner coat but you do want to leave it dull as the slight angle you get from the light coming in will tend to make the surface reflect strongly anyway.
Ultra flat black is also a good way as long as the paint doesn't affect the EPs from going into the focuser. You may want to mask off that area.
Covering the scope will, of course, decrease the amount of light that comes in.
A flashlight or LED will indicate to you how much the light is bothering you and where the really bad places are.

• Focuser - slamhound - August 5, 2002 - 06:58 UTC
  • Focuser Baffle - wilgaze - August 5, 2002 - 21:15 UTC