Turned out to be a fantastic night. By 9 PM all horizons were clear. A bit windy but we lasted till 1:30 AM. Saw a lot of new objects. Mostly galaxies for myself. Jason, Ed and Dunk saw Triton for the first time. A great buzz picking up that one.
Had a nice view of it, but in the faint fuzzy frenzy I forgot to compare the OIII with the NPB
There was noticeably more detail, but then the C11 catches almost twice the light of the 8.
It'd be a really interesting challenge to pick a small number of nebulae to compare one night, I think collectively we have quite a selection of scopes, filters and eyepieces...
I went with Oleg to the airfield on Saturday. Saw quite a few objects.. I cannot shake the image of Jupiter and what I assume to be some of its moons from my mind.
First sequence, sun sets. Second sequence, I adjust exposure and sun light fades as Venus appears. Third and fourth sequences, Milky Way travels overhead (fourth sequence includes tree tops for context).
Last two stills, just two of the best exposures pulled from the 500 stills making up this film.
For those who are interested:
500 images, 20 second exposure once every 30 seconds (via an Arduino). ISO 3200, custom white balance (for uniformity), 18-55 kit lens. All JPEGs (naughty boy) and no post processing save for level/contrast adjust on last two stills in the film.
Hi, yes I think that post processing would make a large difference. And shooting raw if I had a memory card big enough for 3-4 hours.
As it is, JPEGs use lossy compression and so noise reduction didn't do much when I had a play last night. Also tried DSS to stack images on the mac with wineskin, but not very stable.
That looks awesome Ed, really looks like you're "shooting" the stars with your death ray! Its coming, Kate keeps hogging the laptop to watch TV shows. I should get some time to process it tomorrow!
To an observer on the ground, the beam is visible within the "planetary boundary layer" which is the air from the ground up to a few hundred metres, maybe a thousand metres - which is full of microscopic aerosol particles. This layer typically extends to the cloud base which is usually 1500-2000 metres above sea level, and at this point there is usually an inversion layer. The air above the inversion is much cleaner, and the beam effectively disappears above that interface.
Hence its not uncommon to see a laser pointer apparently reaching the cloud base but not beyond that.
Over the upper Blue Mountains the cloud base is usually 1500-2000 metres above sealevel (having measured it on my paraglider), but can be higher in warm dry weather.
Wavy, that then explains why the beam reaches out further when aimed to the horizontal, and 'shortens' when pointed up vertical.
Thanks mate.
Yup... I've noticed the same too especially in the mountains when the cloud base is low. Took me a while to figure out why, considering that the runway length (for example) is much longer than the height to the cloud base. Similarly the distance from Hargraves across the valley to the west is over 10km.
Over Sydney itself the inversion layer is often only 100-200 metres above ground, on a humid night low clouds will form at this level.
the wind couldn't blow out our enthusiasm 
