(meteorobs) Colour camera advice for Sandia system?

[Chris Peterson]

An allsky camera should not experience fogging on the inside. If it does, it 
needs to be opened and allowed to dry. Certainly a desiccant can be used 
inside, but it will probably only provide a small amount of protection. If 
the system is sealed and heated, it really should be fine. The main problem 
is condensation on the outside of the acrylic dome. You need to provide 
enough warm air circulating on the inside to keep the outside surface 
temperature above ambient. It's a balancing act between the emissivity of 
the acrylic (and to some extent, the surrounding surfaces) and its thermal 
conductivity.

Allsky cameras utilizing convex mirrors are very easy to keep dry, since 
radiant heat can be easily applied to the bottom side of the mirror, using a 
heating pad or light bulbs.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Pat Branch" <pat_branch at yahoo.com>
To: <cdnspooky at persona.ca>; "Global Meteor Observing Forum" 
<meteorobs at meteorobs.org>
Sent: Wednesday, August 27, 2008 8:16 PM
Subject: Re: (meteorobs) Colour camera advice for Sandia system?


> To help with the fogging, I might suggest getting a bag of silica gel
> from a craft store. Keep it at the base. When it gets used you can dry
> it in a microwave.