8th May focus shifts

[neil phillips]

One of those times when focus is constantly shifting. Spent more time out of focus than in. But wanted to try my two new filters on the Bresser. Not inspiring. Hopefully things improve

Bresser 127 l astrosolar 3.8 Baader continuum zwo 178mm EQ5 

[Nigella Bryant]

I had the same problem with focusing today, atmospheric turbulence in abundance unfortunately. 

[neil phillips]

46 minutes ago, Nigella Bryant said:

I had the same problem with focusing today, atmospheric turbulence in abundance unfortunately. 

Thanks for that confirmation.  Others have said similar. I do wonder if the cardboard I am using transmits heat into the refractor.  It probably does. But I am uncertain how much that kind of thing matters ? Small effect large effect ? I know I should be using something more suitable. Possibly thinner vinyl wrapped cardboard. If i am not happy over time i may rebuild it. 

Cheers Nigella 

[Pete Presland]

The constraints of the seeing conditions Neil, i think. Focus can be incredibly hard to settle on, generally spend a fair bit of time push the little tie-wrap attached to my 10-1 focuser backwards and forwards, then back again......

All you can do is observe and hope you have it as close as possible in those conditions. I think you can only get it close, as the seeing is so poor at times.