Intra and extra focal images appear to be collimated correctly.
Again, this is only apparent in cold weather below 32 Fahrenheit.
Does anyone know what might cause this?
Edited by NickWDavis, 06 January 2019 - 12:03 AM.
Posted 06 January 2019 - 12:02 AM
Edited by NickWDavis, 06 January 2019 - 12:03 AM.
Posted 06 January 2019 - 12:21 AM
Is the scope/ mirror properly cooled to ambient temperature before you start to use it?
Kevin
Posted 06 January 2019 - 08:23 AM
I agree with Kevin. A warm scope moved outside into the cold will have tube currents that can severely distort your image. Maks and SCTs are particularly prone to this problem, by virtue of their designs, and can require a looong time to reach thermal equilibrium.
http://aberrator.ast...be_current.html
There are threads here on CN that discuss remedies such as pre-cooling vs. thermal insulation. I used to keep my SCT in a plastic box on my back porch so it would always be close to outside ambient temperature.
Jim
Posted 06 January 2019 - 10:16 AM
Is the scope/ mirror properly cooled to ambient temperature before you start to use it?
Kevin
I assume that it was cooled. It was outside for two hours before I started using it.
Posted 06 January 2019 - 11:08 AM
I assume that it was cooled. It was outside for two hours before I started using it.
Edited by Auburn80, 06 January 2019 - 11:10 AM.
Posted 06 January 2019 - 11:55 AM
Posted 06 January 2019 - 02:43 PM
I’ll try letting it cool longer next time and report back.
Thanks everyone.
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