Corona Australis Panel One

[avandonk]

Last night was clear and cold all night. Frost on everything inside observatory as temperature was -1C. No frost on the grass outside as there is still heat in the soil.

Managed to get panel one of a mosaic I hope to do showing all the dust associated with Corona Australis.

Medium Image 5MB

http://d1355990.i49.quadrahosting.com.au/2011_05/CoraP1hdr.jpg

The thermostatic heating of the 300mm lens works a treat as focus has not changed for a month! A month ago ambient was about 15C and last night -1C. Since the fridge is held accurately at -11C and the camera lens held at 19C the optical system does not respond to ambient changes in temperature. At 300mm FL accurate focus has very little room for error.

Bert

[Mighty_oz]

Looks to be a very nice start to another great project , we all look forward to seeing :) Do u have a link to your heating setup for the lens ?

Marcus.

[avandonk]

I use dew heater straps wrapped around the lens controlled by the thermostat here. It keeps the lens at a constant temperature within about a degree C. Hysteresis is the limiting factor.

http://www.oceancontrols.com.au/CET-004.html

They all run from the one 12V DC power supply.

Bert