Lens cover on or off?

Just a tiny silly question. when I put my scope out to cool down prior to using it, should the lens cover be taken off or left on, will leaving it on during this stage encourage condensation, or doesn't it really matter?

From my own personal experience Bill, I leave the scope out for about 30 minutes to 1 hour before I go out, with the cover OFF. I also leave the tube horizontal. This way, the minimum amount of condensation forms and rests on the objective lens (same principle for a reflector). If you have it tilted upwards (more vertical), then condensation, and dew, will settle on it. If you tip it down, the the condensation and dew will form on the focuser! (well, on a refractor anyway.)

Seanie.

Many thanks Seanie.
Bill.

This is what I do with a camera - put it inside a plastic bag and take it outside and leave it for 30 minutes to cool, that way codensation forms on the bag.

Given that a scope is a bit bigger, I would leave it to cool in a unheated room like a porch or shed first. If I can't do that then outside horizontal with the cap off the front and the eyepiece opening faceing down.

Still though, it's hard to avoid getting condensation after stuff has been outside for a while - any more options?

Still though, it's hard to avoid getting condensation after stuff has been outside for a while - any more options?

When I do bother to let it cool, I put a dew shield on (camping carry mat!) and leave it in a horizontal position for a while. I need the dew shield since the corrector plate can quickly fog up without it.

Cheers,
~Al

I leave mine in the conservatory all of the time, it's the coldest room in the house and condensation isn't a problem, so the scope is generally nice and cold when I start.