Hallingskies

New kit syndrome - guaranteed to attract clouds. I've been waiting three months to test the rig I put together and used for this shot...

Thanks. Given the short exposures it was a quite satisfying image, though I think I need to do some more work on the background gradients. This was an afterthought of a project, really, as I was originally going for some RGB on the Cone nebula area (Sh2-273) but clouds kept interrupting the 600s exposures I was after. I swung the rig around to this view as chucking a few exposures away due to passing clouds (and satellites!) wasn't a problem with lot of short ones. I would have collected more than I did but it finally clouded over completely at around 21.00. Things are going a bit better to

That is really good. These phone cameras are amazing...

12 x 15s each in LRGB, Samyang 135mm @f2.8, Atik 460 + EFW2.

Sh2-273, Atik 460, Baader 7um Ha filter, f2.8. 10 x 600s under a full moon...

Narrowband channels all log stretched in Astroart, then Starnetted. Layer masks in PSP used to minimise "Burn out" in bright areas. Gamma Cassiopeiae cloned out of all channels, then RGB combined in PSP, R=Ha, G=SII, B=OIII. H alpha overlaid as luminance to retain detail. For stars, the unstretched narrowband data was RGB combined in PSP, then saturation lifted to bring up star colours. Star layer pasted over nebula layer in screen mode. For this iteration, the log stretch for the narrow band channels was milder resulting in a less overpowering green from the SII channel and a more subtle r

Clear nights....clear nights. Nope, don’t know what they are, though the concept seems vaguely familiar.....

Yes, my old work HP had a battery life of about 7h, though I never used it outdoors in the cold! Re. the mini computer, others here are better qualified to advise you. The idea would be to have your data and control feeding to the mini at the mount, with a remote connection to a computer that you could use to check now and then that everything was working ok (rather than continuous monitoring). If your pockets are deep you might want to think about one of these...

Laptops are real power eaters and you would need a biggish battery to run that plus your astro gear for more than three or four hours. As an example, my Lenovo requires 65W: if you assume a 12v supply, that’s about 5A straight off. If your astro equipment chews another (let’s conservatively say) 3A, that’s 8A total for every hour. You’d need a 100A/h battery to get you through a full night’s session by my reckoning. I think lithium’s at that capacity are coming in at around £600, lead/acids are a lot cheaper but you can’t run them below 50% too often without wrecking them. Be interest

Narrowband channels all log stretched in Astroart, then Starnetted. Layer masks in PSP used to minimise "Burn out" in bright areas. Gamma Cassiopeiae cloned out of all channels, then RGB combined in PSP, R=Ha, G=60/40 Ha/SII, B=OIII. SII overlaid as luminance to retain detail, colour balance adjusted in PSP to make it a little less green (strong SII data!). For stars, the unstretched narrowband data was RGB combined in PSP, then saturation lifted to bring up colours. Star layer pasted over nebula data in screen mode. Final colour/luminosity balance adjusted in PSP, saved as jpg....

Icy surfaces will be the main problem. The track down to my obbo is a sheet of ice now and I don’t dare use it, but I plan to set up nearer the house tomorrow night to carry on testing my new “portable” set-up. Take extra care, folks...

On January 21st. they are about a degree apart, with Uranus due south of Mars. There's a nice half Moon just six degrees to the east of Mars as well.

This is a superb image, Richard, one of the finest I've seen on these pages. You have processed excellent data with a fine touch.

I run one in my glass fibre dome because natural ventilation Does Not Work - the condensation was horrendous. I did put some P section tape around the flange of the dome and the opening hatch runners to cut down the air ingress. I have the dehumidifier wired through a humidistat and it holds the obbo nicely between 55 and 65% Rh. If things are really soggy it might come on three times an hour for around 3-4 mins a time, usually much less often. The RH readings on the datalogger go a bit haywire when things get below freezing but there is so little physical water in the air that it does

I’m not sure that RH actually means too much below 0’C as the water left in the air is from the partial pressure of ice rather than liquid water. I’m sure the physics graduates will put me straight but I think there is very little water in sub zero air. I used to run a heater in my obbo because I was worried sub zero temps would damage my dessicant dehumidifier but touch wood things have been fine without it these past couple of winters.