DaveS

After discussion with @Jkulin elsewhere I ran an initial G2v calibration trial, finding that the Blue channel needs 1.74x the exposure that the Green and Red channels need. I think it was @Laurin Dave who first alerted me to that possibility. I have no idea as to when I will be able to get more data with the calibrated values as the moon is now getting too bright for worthwhile RGB. H-alpha is still just viable, but think there is very little here.

Thanks Andrew, but the background is very uneven despite some pretty fierce gradient removal iterations.

After fighting many battles with rubbish data I've posted my poor effort. Not worthy of the kit used.

This is a truly horrible image of NGC 3718 captured on the 16th and 17th with the ODK 12 / G3 16200. 15 x 600 sec subs of Red and Green, 21 subs pf Blue. Stacking in DSS with full calibration, linear stretch in Affinity then Gradient Reduction (Many iterations), RGB synthesis, and colour balance (Two iterations) in Astro Art 7. Also applied heavy noise reduction. I've found that the 16200 camera with Chroma filters needs a lot more Blue that the other channels, and could probably use 900 sec subs rather than the 600 that I normally use. If I were getting a camera for the ODK now there is no way I'd be looking at a 16200 camera. Old tech, noisy and insensitive. Might eaven sell it and get one of the IMX 455 cameras.

I've been bashing at this with the ODK 12 and 16200. Could do with a more sensitive camera but can't afford more aperture!

That's very good. Just started on that one myself, though results so far are nothing like as good. Only got 4 hours so far, and no idea when I'll get more with an ever brightening moon and shortening dark.

+1 for Ventusky Last night I had CO and MO saying no chance, but could see the sky clearing so checked Ventusky. Got a report of clear until dawn so set up for a 4 hour run on NGC 3718. Got the full complement of subs, and when I went out to shut up shop at 4.30 the sky was still clear, though starting to get light.

https://www.nasa.gov/feature/new-horizons-spacecraft-answers-question-how-dark-is-space Even the Hubble space telescope suffers from light pollution in this grubby bit of the inner solar system. Time to put a humongous gert light bucket out in the Kuiper belt

Ooh, that's very good! The Rho Ophiuchi region is *very* low.

The Moravian G3 16200 on my ODK 12 has a light leak somewhere. I had been getting a streak of light on my subs of M106 after the meridian flip where the camera is east side, and where the top cooling vents are pointed at the obsy CCTV LED flood lights. Has anyone else with a G3 camera had light leaks? I still have some more investigations to do, as I want to find out if the light is getting in behind the shutter or bouncing around and coming in through the filter wheel.

I found light could get in through the top surface of the camera. but I think I have blacked out all the stray light in the obsy. Trying a two hour run.

The most likely other light was coming from the 4-way distribution block which has a neon indicator that I've since covered in black tape. There is also a 12V PSU on the floor that has an illuminated display of voltage. I've covered that with tape too. When it gets dark enough I will try some ideas to track down the source of the flare.

Well, it's not the CCTV camera, since that blasted streak is still there despite turning the camera off. I have no idea any more where it could be coming from.

No OAG needed, it's on the DDM 85 which is encoder guided. I'll add that I have the camera turned off now, plus I've been round putting black tape over all the LED pilot lights, just in case.

I had some light ingress problems which I think might be due to the IR LEDs of my obsy CCTV, after the meridian flip Before flip After flip No calibration, just a brutal linear stretch, but the streak is visible in the stacked subs given a more gentle stretch. I have a Hoya IR76 on order from EO which I hope will cut off the iR LED emission before the Luminance pass-band.

QHY also do a short BF version of the 600M with 12.5mm BF like the 268.

Yes, you posted just as I was hitting Submit Reply.

2" mounted filters will be marginal depending on the focal ratio of the telescope and back focus from the filter. 50mm unmounted are safer.

They make cameras with both grades of sensor, so it's not just to put one over on ZWO

Different sensors from the Astrograph site

Very nice indeed Tony. Had a go at this last year with my TS Apo and ASI 1600 but was nothing like as good as yours. Currently bashing it with the ODK 16200 combination. H-alpha will make a difference as there are HII jets being ejected by the central black hole, but you'll need a shed load of data. I got 12 hours last year and it barely made a difference.

I think the Bortle scale was developed in the American South West, ie low latitude dry atmosphere conditions, so a lot of his DSO criteria just don't apply this far north.

But not if you're looping exposures and adjusting focus between each. all that PS palaver is just wasting time.

Hehe. I just need a white persian cat to complete the picture .

By the way, the link came up with a 404 error.