Thoughts on which imaging rigs to concentrate on

[Filroden]

It's by no means certain. Large clouds passing over all the time but as it cools I think it will clear (and the wind is picking up). I'm amazed by the cooling on the camera. From an ambient of about 8C it went down to -30C and says it's only using 44% power!

[Gina]

Here's the auto stretched 30s integrated image.

[Gina]

Found the set of 60s g440 -30C darks.

Integrating pixels.  There was one duff dark frame so this is with 79 frames.

Edited November 23, 2016 by Gina

[Filroden]

Are you visually inspecting the darks?

[Gina]

Oh - errr no forgot that   I'll check shortly on the ones I've done and redo if necessary - also the next set.

[Filroden]

I just wondered how you spotted you had a bad one. I never check bias/dark subs and just assume the linear fit algorithm will weed out the bad data.

Now I've hit a snag. Even 30s at 400 gain is over exposing my image. Hopefully its because there is still 20 mins until astro dark but I may have to drop back to 300 gain.

[Gina]

PI spotted it.  Checked the rest in Blink and all OK.  Couldn't find the 120s darks so taking again.

Or reduce exposure to say 15s

Edited November 23, 2016 by Gina

[Filroden]

I think 400 gain is too high for LRGB. Probably fine for narrowband. Even at 15s it was looking overexposed and I did not relish the though if tripling my image count so I'm dropping back to 45s at 300 gain and no offset.

[Filroden]

At 300 gain the 4 brightest stars are overexposed in L so should be fine in RGB. And I think 3 of them fall outside my crop area anyway  Looks like 45s / 300 gain is my limit.

[Gina]

Ah - I see - didn't realise you were doing LRGB.  I think I used a gain of 150 for RGB on M31 but that was with an f2.5 lens.

[Filroden]

I could drop to unity but I doubt my mount would be happy much above 60s, particularly in this wind so I'll stick to the higher gain and lower exposure. I've just checked more frames and the cores of more stars are over exposed in L but only just. Hoping that the RGB filters will do enough to bring it back within range. It's useful to test these things and know about them for future projects. And I just found SGPro has a frame grading tool so I can drop really bad frames even before copying them over to PixInsight!

[Gina]

Just run my all sky cam and against prediction the sky is clear ATM   But there's rain forecast so might not risk it.

Edited November 23, 2016 by Gina

[ChrisLX200]

Just looked at mine and it's cloudy - and likely to remain so (after saying for the past 3 days it would be clear).

ChrisH

[Gina]

There seems to be cloud coming in now   The focus is out but the indication is clear enough

[Gina]

Clouded over now.

[Gina]

Forecast is much better for tomorrow night but we'll see.

[Gina]

Currently capturing 120s dark frames with gain of 440 and -30C.

I have master bias and darks matching some of the lights but next to sort out is the master flat.  The flat frames I have for the dates in question need recalibrating against the new master bias and appropriate master dark.

[Filroden]

I've had some clouds come over too but it's given me the chance to capture 30 more darks at the new temperature. It's starting to thin out so hopefully they'll all be done and I can get back to lights.

[Gina]

Calibrated and integrated the flats from 2016-10-13 as per the book and here is the auto-stretched result - it's different from what I got before - doesn't show the vignetting in the corners I got before.  Puzzling!

[Gina]

Having produced new masters for bias, dark and flat for October I could either run BPP again or go through the more detailed processing in PixInsight.  On the whole I think I'll try BPP again and see what difference making a proper master bias has made.

[Filroden]

I find the more detailed process doesn't take too much longer once you get used to it. The only thing that can take time is assessing sub quality and weighting the subs during integration. You can, of course, just let PixInsight assess and weight quality using either method but I like the sub-frame selector script.

[Gina]

Downloaded and integrated the 80 120s g440 -30C dark frames.  Here's the auto-stretched result.

[Gina]

Took the set of Cygnus Loop SII light frames, looked at them carefully with Blink, dumped 3 and chose the best for reference.  Then processed the remaining 106 light frames with BPP using the master bias, dark and flat calibration files.  This is the result auto-stretched.  It's far better than I got before   In fact far better than I've ever got before in SII including captured with the Atik 460EX mono.  I had to go back and double check it really was the SII subs!  Total capture time of subs integrated was 212m = 3h 32m.

[Gina]

Tomorrow I plan to re-do the Ha and OIII data with the new master calibration files.  I can now go to bed happy with my latest achievements - I think I'm beginning to get the hang of PixInsight

[Gina]

Now processing the Ha light frames having checked in Blink - no more rejects, 105 frames, selected best frame to use as reference and set up everything in BPP.