How many here use a gas purge...

...to keep humidity levels down inside the camera?

I'm trying to get a feel for how much of a concern it is.

Thanks!

Jeffery, I do not use a purge yet, but plan to when I return from vacation next April. I have a 12"LX200 classic in an observatory. It has been there for more than two years, and everything worked fine until recently. Suddenly, it has been fogging up inside of the telescope, and the primary mirror is also covered with frost. That really reduces the seeing. It is funny though, if looking at bright objects, it is hard to tell that the whole inside of the scope is covered with frost. I will watch any thread that developes from your question.

BTW, I just planned to get a small canister of dry nitrogen and work out some way to fill the scope with it. Once the water/air is purged from the scope, I am certain that it will remain pretty dry and that I can purge the scope every evening that I use it rather easily. I currently plug the eyepiece mount with a vented film canister filled with a dessicant.

Ted