Gina

I think the next thing may be to assign the two images to different colours and see what we get. I have the OIII as well so could do a 3 colour image.

Comparing the 1:1 and with offset I still think the 1:1 is best. The two sessions were taken on the same night one following the other and conditions seemed constant AFAICT.

Been playing with PixelMath both multipliers and offsets and can't seem to find a better match than 1:1 though Ha5-(Ha3-0.02) is pretty close I think. Here's a screenshot from PI auto-stretched.

Auto stretched Ha3 as comparison.

I've registered the Ha 3 and 5 nm integrated images and applied PixelMath Ha5-Ha3 directly ie. no offset or gain modifiers. Here's a screenshot of the result auto-stretched in PI. I haven't bothered to play with the stars. The Rosette which is supposed to contain NII is looking quite bright with NII but whether some of the other objects contain NII I don't really know.

Here's the 430 x 10s Ha subs with curves applied. Needs DBE applied to smooth the background levels which I think would improve things considerably. Seems to me that using a vast number of short subs really helps with this high dynamic range target. I think I shall have another go at this with the same lens but framed to put M42 further from the edge. I also want to capture OIII subs. Advantage of this lens is the wide f2.5 aperture.

I think I need to separate M42/43 from the Flame and HorseHead area. A longer focal length would be better. Must try the 200mm f4 Super Takumar. M42 will want the Esprit 80ED telescope. I've imaged M42 and companions before but not with such a high resolution camera. 4656×3520 px versus 2750 x 2200 px.

Here's the integration of 32 60s subs.

That's exactly what I did (at least I think so) registered to the same exposure sub.

Hmm... rather a lot of failures in the StarAlignment process - lost nearly half of them 32 left.

I'm doing the 60s subs next. Made a mistake above the 94 I thought were 30s were actually 20s so I need darks for that.

Integration of 430 10s Ha 3nm subs. Screenshot of PI auto-stretch and full resolution image saved in PI as PNG.

StarAlignment complete now integrating...

StarAlignment of the 10s subs now. I'm completing each set before going on to the next as this way yields some results more quickly.

Now calibrating... This will take some time Discovered I haven't got 2s darks at gain of 440 though so maybe get some darks tomorrow. Plenty to do with all the rest though

All capture files from last night checked with Blink and duff ones dumped into the Junk folder. All 3nm Ha since the focussing wasn't working. Good subs :- 430 at 10s, 94 at 30s, 100 at 2s, 29 more at 30s and 45 at 60s. So... totals are :- 2s 100 10s 430 30s 123 60s 45

Seems I processed those Ha 3nm subs from Thursday night so now have integration of both Ha 3nm and Ha 5nm ready for sorting out subtraction.

Time to get back to data processing I guess. Hundreds of files most of Orion but some of Monoceros/Serpens from Rosette to Eagle. There's 120 odd Ha 3nm subs from night before last and around 800 from last night Should keep me busy for a while

I've brought the laptop indoors and shut down the observatory. The laptop felt just warm to the touch so should have been alright. I guess I'm just going have to bite the bullet and sort out the Raspberry Pi and INDI etc. Should be able to get image capture working alright - it's working fine for my all sky camera - the more difficult area is all the rest. Don't really know what I'm frightened of - must be getting old I guess - nope, gotta fight it!! Mini/micro/computers/processors and interfacing was my job when I was earning, though that was several decades ago but I've been keeping my eye in

Cloud has come in now anyway, so that's that.

I know it's very cold out there - the camera was showing -6C without the cooling on

I doubt if I can fix it tonight. The slow download speed shows a problem with the laptop. Previously this was solved by bringing the laptop indoors and warming it up before taking it back out again. I would have thought that a pet warmer set at 40C would keep the laptop warm but it's not working Apart from the laptop there is also no reason for the focussing not working - everything is connected as it was working fine earlier and I haven't actually touched the rig. There is a very cold breeze tonight straight out of the north-east and little protection from it. I really need to dump the laptop!

Nope!! Still won't work Tried a remote reboot - no joy. So do I go out to the observatory and get frozen to death or give up on capturing anything other than Ha 3nm subs?

Ans still downloading slowly Captured 100 odd 2s subs and now capturing 30s subs. Be time for meridian flip soon.

Thanks Still downloading slowly - 12s per 32MB file over CAT6 1Gb/s system - normally 2-3s per file. I'll give it a bit longer then try the focus again. Meanwhile, I'm grabbing 20s subs.