Keeping Telescopes In Sunlight.

[Wedge]

Hi There.

I keep my Omni XLT 150 permanently set up in my room, facing the window, (although you can only see the wall through the eyepiece), ready to be unassembled and taken downstairs when observing.

Today, i noticed that there was a lot of sunlight falling through the SSE facing window onto my telescope, making it warm to touch.

Could this cause problems if it continues over the days?

Will it reduce the optical quality tonight, and over other nights, or am i just being paranoid?

[AstroTiger]

cannot really see how.

I mean telescopes need to stand up to the elements like extreme cold in the winter (if in an obsy) the dew as well.

anyone else any thoughts on this?

Personally i'd say u should be fine, if the optics were pointed at the sun all the time then i could see the concern.

Otherwise? hmmm, no i'd think u were ok

[Andrew*]

collimation issues with all that expansion/contraction??

Andrew

[GazOC]

Another issue could be with the adhesives in the scope starting to run???

[philsail1]

Yes, I would agree on possible colimation and adhesive issues. Could also be a danger of someone knocking the scope over and doing damage to it (or themselves) - or maybe a child playing with it and inadvertantly pointing at the sun!!!

regards,

philsail1

[John]

With Skywatcher scopes I've found that the black anodised parts can fade to a sort of bronze colour with lengthy exposure to the sun. They still work fine but it can look a little unsightly.

John

[GazOC]

Wedge, I guess the general advice don't leave it in the sun unless you have to...

[The Warthog]

If we have a run of good weather in the summer, I often leave my scope set up in the back yard. I usually cover it with a large towel, though, so the paint won't fade. I haven't had any problems with collimation or glue.

[supernova]

close the curtains or cover it with a white towel

[Hugh]

Mine lives by our S. facing patio doors which do get the sun. I generally cover the scope with a light coloured cloth and pull the vertical blinds across to keep the direct sun off the scope.

The main issue for me is cooling down time after a warm day... Even when cold outside, it get hot behind glass - melting adhesives and the like are something I have considered but the scope has never got hot to the touch, so I hope it will be OK.

Incidentally, I recently read that it's advisable to keep your power tank type portable battery supply well out of the sun as it shortens it's life :?

Hugh

[Astroman]

My scopes are set up in the dome IN ARIZONA all summer long. I've never had any trouble. I'm sure yours is in no danger.

[centroid]

My scopes lived in my Roll-off-Roof obsy, which is dark green and has a felt roof.

Therefore it does get pretty hot in there on sunny, hot summer days.

When I found the temperature had reached over 40C in there, I did have concerns, but the scopes hadn't sufferred any ill effects at all.

I have since installed an exctractor fan, controlled by a wall mounted thermostat, which switches the fan on when the inside temp reaches 27C.

The big problem with direct sunlight, is that it fades the colour in most materials.

For your own peace of mind, as has been said, throw a cover over the scope.

Dave

[Astroman]

We had a record high summer this year, 37 days over 44ºC. Scopes show no ill effects. Fading from the sun's UV can be esthetically unpleasant, but isn't a functional problem.

That said, a friend of mine once had one of the newer C5's I think, that had the secondary glued to the corrector plate. In the heat, the glue melted and the secondary drifted to one edge. Celestron replaced it for him.