M78 area

[fwm891]

Longer session last night. Spent some time checking and adjusting the mount's PA. Then to hours total integration time on M78 and it's surrounding area. 20 subs: 10 x 240s and 10x 480s.

Details:

iOptron CEM60 standard mount on tri-pier

RASA f2 OTA

ASI294 MC Pro OSC camera with Idas NB-1 filter

SG Pro as capture software, Processing mixed APP & PI

[AbsolutelyN]

Looks great. How are you finding the star shapes in the corners? Rather curious about how easy it is to get the right spacing for good flat field. Cheers, Tristan

Edited January 21, 2020 by AbsolutelyN

[fwm891]

43 minutes ago, AbsolutelyN said:

Looks great. How are you finding the star shapes in the corners? Rather curious about how easy it is to get the right spacing for good flat field. Cheers, Tristan

There's very little tolerance with the f2 RASA. I've made my own spacer/filter holder to give me the 25mm back focus. The filter at present is not sitting quite square on and causing a few distortions (left to right in above image) though that may also be due to the IDAS NB-1 filter not being well corrected for the f2 light cone. Correcting the mount PA last night has made a big difference and something I will check more often especially after working round the mount / tri-pier.

[AbsolutelyN]

33 minutes ago, fwm891 said:

There's very little tolerance with the f2 RASA. I've made my own spacer/filter holder to give me the 25mm back focus. The filter at present is not sitting quite square on and causing a few distortions (left to right in above image) though that may also be due to the IDAS NB-1 filter not being well corrected for the f2 light cone. Correcting the mount PA last night has made a big difference and something I will check more often especially after working round the mount / tri-pier.

Thanks .... just ordered one from FLO, hoping fiddly spacing doesn't make me regret it ...

Edited January 21, 2020 by AbsolutelyN

[alan potts]

That's very nice Francis, one of the most disappointing visual objects in my view but you have done it proud.

Alan

[astro mick]

Looking good Francis.

Mick.