It Did Actually Clear...

[martinastro]

...last night. In fact, it was a stunning dark sky with no Moon and bright stars. After being starved of trans skies for so long the stars seemed all the more brilliant. Some good meteor activity last night to. High level cloud moved in and blocked Boatini's location again. I only managed to get one image of the sky through the cloud. Hardly great but proof, if proof were needed, that there was actually a good clear sky in N. Ireland. Verical shot showing Cass and Perseus. Capella at bottom and M31 at R. Very noisy I know, I don't know why the nosie has got worse. ISO800, 30 secs at 28mm F/2.8.

[Paul]

Very niec shot Martin - you got the Double Cluster nicely dead centre!

I don't know why the nosie has got worse

Ambient temperature I'm afraid.

[Steveo74]

Great shot Martin! Have you tried Neat Image to remove the noise?  I think it would work well on that great shot you have taken...   

[martinastro]

Thanks Paul and Steven. That explains it Paul. I thought something was wrong with my camera. I had a shot of Uma above the horizon but it was so noisy I deleted it.

Steven, I did try neat image and it works extremely well however I find it kills astro images to much. The overall image turns too soft and some of the stars are lost. Unless there is a way of doing it I don't know about regarding the settings?. I won't give up though. Must give it another go. Cheers 

[brianb]

In fact, it was a stunning dark sky with no Moon and bright stars.

Yeah, it started off terrific here too. Then stratocumulus moved in (around 2330 UT) and it wasn't so good after that - a few temporary clearances - a very light "drizzle" shower around 0100 and a slightly heavier one around 0215 by which time there was fairly extensive high cloud visible through the gaps, and the SC was obviously hiding something with precipitation potential, so I called it quits. Just as I was collecting the tripod there was a bright meteor - about mag. -2, very likely a Perseid,  visible in the NW (Bootes region) visible through a gap in the cloud cover too small and too low to be useful for observing. Very warm despite the breeze, which at least deterred the unidentified flying objects with sharp teeth from attacking me.

As for the image noise - I thought it was "well known" that sensor noise approximately doubles with each 7C rise in temperature, and it's pretty warm these nights! I suspect the best noise removal routines for star photos are those which selectively unsharpen the sky background, leaving areas with sharp gradients (stars) alone. However this would still have a strong negative effect on "faint fuzzies".