Sometimes it works, sometimes it goes all wrong.
Friday night - I left the Bahtinov mask on for imaging the first target - doh!
Friday night's second target was a Hyades mosaic. Unfortunately, even though is appeared to be a darker than average night, there was too much "murk" in the air. The result was a "headlamps in the fog" effect on all the bright stars - especially Aldebaran:
(http://www.markshelley.co.uk/Astronomy/2017/Hyades_headlamps_in_fog.jpg)
On a less murky night the result would have been good. But Friday night wasn't good enough. I think it is good for people to see images that never worked out well because, in fact, you often learn as much from the failures as the successes. Not only is there a "headlamps in the fog" effect but the skyfog gradients were worse than usual.
This is definitely an area I want to try again because the bright stars and the dust clouds make the Hyades a very interesting region. By the way, it was 30 minutes total exposure per panel, making 2 hours in total - Sony A7S on Tak Epsilon.
If you put an image like this on the average astro-forum and ask what went wrong most of the replies will be "dew and condensation on the optics and/or sensor". Well no, sky murkiness was definitely the cause of this and it ruins more images for me than any other single factor (including leaving the Bahtinov mask attached!)
Mark
What a shame Mark that would have been a great image otherwise.
It's amazing how we can image over and over again yet still make a basic error like that. I discovered tonight that I had left the central bolt loose on Friday after adjusting the alt/az boots for PA. I can't believe l got M78 in the circumstances. Then tightening it up tonight I had to check the Pa over again. Duh!
Cqrole