30 replies to this topic

[Dan_I]

Why the manufacturers don't extend their tubes a bit farther up is beyond me. I guess they're not astronomers worried about contrast.

Personally I prefer a short tube with a long, flocked dewshield (like this) than a long tube: more rigid in the critical spider and focuser areas where the metal tube can flex, easier to transport.

Edited by Dan_I, 04 September 2023 - 11:36 AM.

[fmendes]

Personally I prefer a short tube with a long, flocked dewshield (like this) than a long tube: more rigid in the critical spider and focuser areas where the metal tube can flex, easier to transport.

 

Even in that case, nice rigid dew shields would be welcome. A flat panel on top of a flexible dew shield will likely bulge. I'll see if I can find a nice aluminum sheet to make a rigid dew shield for my SW Quattro 200P. For storage, it can go around the telescope, between the two telescope rings.

[fmendes]

Maybe this idea will deserve its own topic, but I'll toss it here. Instead of moving the flat panel away from the telescope, I remembered my studio softbox. It does have a mesh that can be put in front of the softbox to better control light and avoid it going stray. I'm thinking about applying the same idea here. Would just put the mesh in front of the telescope, and then the flat panel on top. I know, risky, as this introduces new objects onto the light path. But if I do it right, light from the flat panel will only reach the primary mirror.

 

Comments?

Edited by fmendes, 05 September 2023 - 10:20 AM.

[JRL40]

Astrogoods.com sells sucks masks Starman was talking about.  It's called a turned down edge mask, it'll also do the same job as the mirror clip mask that hides your mirrors clips.

[astrogeek64]

Even in that case, nice rigid dew shields would be welcome. A flat panel on top of a flexible dew shield will likely bulge. I'll see if I can find a nice aluminum sheet to make a rigid dew shield for my SW Quattro 200P. For storage, it can go around the telescope, between the two telescope rings.

I've used aluminum chimney flashing material, flocked on the inside and assembled with Velcro, so it can be laid flat when not in use.

[fmendes]

I've used aluminum chimney flashing material, flocked on the inside and assembled with Velcro, so it can be laid flat when not in use.

 

I bought at the junkyard an aluminum door for $3. It's already flat and cut on the right size, I just need to build a mangle (?) to bend it into a pipe.