Thoughts on heaters

[rdagger]

What is the main purpose of camera heaters? Are they for picture quality and lens defrosting or to protect the electronics and moisture?
Are they worth paying extra for and are there any downsides?

 

[nayr]

they wont defrost or deice a camera; if its a fixed camera I think they are pretty much worthless.. just consume more electricity than nessicary as the only moving part is the IR cut filter and cold weather rarely if ever effects them.. electronics can handle extremely low temperatures; and there is no moisture in the air when its below freezing out.