Collimation blues & Christmas hues

My optimism regarding the new spider was short-lived when a clear sky gave me the opportunity to try it only to reveal that the collimation was far from happy. I wasn't sure why it was so amiss so opted to wait for daylight before attempting to rectify it. I therefore put the camera on the apo and decided to make another attempt on The Heart Nebula in Casseopeia. With the sky looking fairly transparent I was surprised that the first sub looked very washed out (see enclosed example). The following exposures didn't get any better so I began to suspect a filter problem. I then realised that this was my first photo session since the town's Christmas lights had been switched on and, although not that obvious, the sky was awash with multicoloured illumination that even the CLS filter would struggle against. I resigned myself to the problem and carried on. As an experiment I added a batch of shorter exposures into the final mix in the hope they might help produce a more contrasty image.Whether they did or not I'm not sure but I was pleased to get a recognisable result after a lot of processing. I try not to wish my observatory was elsewhere sometimes. Details: Megrez88 apo with Baader MPCC. 10x 10 minute + 5x 5minute exposures @ iso 800 with CLS in DSS, CS2 & XAT.

No comments: