From: Alan Friedman <alan@greatarrow.com>

Date: November 29, 2007 7:27:51 AM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Raising a heat issue


Hi -


If I have my 10" scope out for a long evening of observing at a rural star party and dew promises to be an issue I will set a heat strap on the dewshield at low so that I don't get shut out early. But I am loathe to do this at home if the seeing is promising for high resolution imaging. Much of my work is done in the hours before dawn - for this I set the telescope out the night before (I store it in an unheated location) with the cover on and a tarp over it. When I get started, I place a 1/2 foam blanket around the dewshield and extending out beyond it by several inches (the dewshield is about 12" long itself) - this small bit of insulation seems to be enough to forestall the onset of dew during an hour or two of imaging in the pre-dawn hours. 


best,

Alan




On Nov 29, 2007, at 8:31 AM, Ray Byrne wrote:

Hi Duane,


I've started using my dew heater strap and wonder what effect it could possibly have on my planetary imaging efforts. On my last outing I gave up after 4 hours of trying to image Mars it was wobbling like a jelly. My friend Mick Hyde who lives about a mile away and lives in similar surroundings managed to take some great shots with the exact same gear minus the dew heating but inconclusively about 30 minutes after I'd packed it in for the night.


Any comments anyone?

.