Jump to content

Narrowband

Rubbish Chain, Rubbish sky


DaveS

Recommended Posts

I got this data on Fri 20th, and I think it will be the last (Only) galaxy image I do this season, which has been unremittingly miserable.

6x300 sec each R, G, B through ZWO filters with the ASI183 on the 80mm f4.4. Unguided on the DDM60. Capture in Maxim DL6, processing in AstroArt 5.

5adee3a4eb0d0_FirstRBGStackflatandbias.thumb.jpg.820b7e157e39cd1dda8db5da4f8cdef2.jpg

I think I missed out one or two galaxies at the top of the chain, due to CduC slewing to the wrong point. I also put all the data together into a synthetic mono version to try for better S/N. A couple of satellite trails as there weren't enough subs for the sigma stack.

5adee3a80edb2_SyntheticMono.thumb.jpg.edd71cc6eac1a971e944f37b318f0ea7.jpg

That's it for this season. Probably start NB when it gets dark enough in June-ish.

Link to comment
Share on other sites

I'll just add, that there's a fair bit of tilt in the system, see the elongated stars in the bottom left corner. Possibly the camera rotator wasn't seating itself properly.

Calibration was with Flat and Bias only as my Dark frames were rubbish, I'll have to re-do them.

This is a very slight crop, to get rid of some amp glow.

After stacking I applied gradient removal as there was a lot of LP / Moon glow. Trichromy was followed by gradient removal > adaptive subtract and a white balance. Most of the heavy lifting was with DDP followed by several rounds rounds of histogram stretch, and some low-pass filtering to get rid of the worst of the noise.

This was a truly rubbish night. When I started delta leonis was barely visible, by the end even the "sickle" of Leo was barely visible. If I hadn't been going stir-crazy and desperate to be imaging *something* I wouldn't have bothered.

Link to comment
Share on other sites

Thanks guys

On reflection, I have to say I'm pleasantly surprised that the data was as "good" as it was, and after checking on Stellarium it looks like I *did* get all the chain, and M87 as well.

John, I had software problems too, the program that refines the sky model (Among other vital functions) threw up .net framework errors, and in the end wouldn't even start properly so I had to make the exposures using only the basic whole-sky model. Fortunately at only 5 min, I think I "got away with it". Still, the stacks had slightly ragged borders, a sign that longer exposures would have trailed.

Link to comment
Share on other sites

I managed to get some reasonable Dark Frames, enabling full calibration, and allowing me to post the full, uncropped frame.

5ae0d720ca2cf_RGBStackfullcal.thumb.jpg.38c260367b7150a340962692709578b7.jpg

As you can see, there's still some amp-glow but never mind. I boosted the blue channel a touch as I thought the previous version was a bit too yellow, even for these ellipticals.

Link to comment
Share on other sites

Well done on persevering, it has been hard lately.

Apart from the rubbish weather I cannot use my rig at the moment as the backyard space is currently taken up with a recently purchased second hand Pulsar dome        (I’m ever the optimist).

By the time it’s moved to it’s interim location the moon will be out of the way and still a couple of hours of Astro darkness left up here. 

Keep on imaging?

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.