Jannis

Is that the stacked image, or a single frame? If it's the stacked image, what stacking method are you using? I'd suggest trying kappa-sigma-clipping stacking mode and see how that turns out if you're not already using it. That should also remove satellite trails, which it looks like you have a couple of? Edit: More info on different stacking methods: http://deepskystacker.free.fr/english/technical.htm#stackingmethods

Really nice images, and amazing you can get that much detail from only 10s subs!

Thanks! :) I plan to add more data to it when able, but adding data to it for the rest of the season probably won't be an option. I'm also not sure how well it would work to add "moonless" data to an image like this where the moon was right over the target and lit up quite bright?

Thank you for the feedback Olly! I have started to also prefer a bit of noise instead of washed out details. I compared the before and after, and i didn't see much lost details compared to before NR though, so maybe i did a mistake somewhere during processing. I will try a reprocess and see if i can make it better. It might also be that 2x drizzle stacking with only 13 low res frames was a bit optimistic, so i will try again with no drizzle and see how it compares. I will also try to be more gentle with the NR next time.

After being sick for what feels like an eternity, followed by two weeks of clouds and wind, i simply could not just let this night go as it was said to be yet another week or two with clouds on the way. With my main scope not quite ready for use yet, i quickly hooked up the QHY5L-II-M to a canon 50mm lens, attached a 7nm Ha filter, and started looking for a decent target. I didn't need to look long before i saw Orion, and then it was set! As the moon is currently 78% lit i must admit i was a bit worried, but i think the end result turned out OK, especially considering the relatively little data of just about 1 hour. Exposure is 13x 300s (and 35x 30s for the core of M42) with the QHY5L-II at gain 12. The lens is a Canon 50mm F/1.4@F/2.8 Darks applied to 300s exposures, but no flats or offset. Stacked in DSS, processed in PS and cropped to 16*9 size.

Gave this target a go over the last few clear nights with the QHY5L-II Mono and a 50mm lens (stepped down to F/2.8) for a wide field of view. No guiding as this this is usually my guide cam, but at only 50mm there was no problem with tracking at 300 sec, and only minor issues at 600 sec. Ha was quite bright in the 300 sec exposures, but OIII was much more faint then I had thought and barely showed up in the 600 sec exposures. After some hours of OIII it started showing up though. Although low res, I think it turned out quite ok. Ha: 37x 300s + 28 dark OIII: 27x 600s + 72 dark Total exposure: ~7.5 hours Alternative version with increased colors, but maybe it's a bit too much..?

You need a C-mount to 1.25" adapter, something like this should work: https://www.ebay.com/itm/C-Mount-to-1-25-Video-Camera-Barrel-Ring-Adapter-for-Astronomy-Telescope-CO/202366475568?hash=item2f1dfb5d30:g:QbEAAOSwCGVX5KLr Unscrew the cover, unscrew the lens, attach the adapter and you're ready to go. For sensor protection i also recommend a filter of some sort. UV/IR for refractors, while clear glass should be fine for reflectors. If PHD can't connect to camera ("QHY not found"), it's probably because you use a driver that's too new. Try installing v. 1.44 and see if it detects camera. I've shared the old driver here: https://www.dropbox.com/sh/ilmsot3rgeg99bn/AADv7oR0W4oVmLq0NfWtENs0a?dl=0

If you're sure you sorted the list by time and not score, and it's decreasing steadily, then i guess it's possible that the dew formed slowly. It's also possible that moonlight/light pollution gradually caused more and more problems, but with that large difference (300 va 100 stars) it's less likely. Personally i like to keep all frames except those that stand out as much worse then the average, but in your case where DSS don't show a sudden change in the score that's not so simple to determine. I usually filter out those with significantly less stars detected, significantly higher sky background %, and significantly higher FWHM - then stack the rest. In your case I would probably just quickly look trough the pictures and see if you can visually see any sudden changes. I would probably only keep the 105x 60s exposures (and maybe the 5x 120s, stacked in a separate group in DSS) and discard the other 30/22/10//9/4/3/2 exposures.

As for dew; add all images of identical exposures in DSS and register them. Sort them by date and time, and you should usually be able to see quickly which of them to discard. You'll see that most of then have roughly the same score, stars detected, and sky background %, - then suddenly stars detected will drop together with sky background % and probably also score. This is usually where dew or clouds are causing problems for you. Discard ALL frames that stands out as significantly worse, or they will cause both a worse stacked image, and with uneven color and brightness.

I had a look at the stacked image, and i don't think the image is too red. The colors were just not aligned well. As far as ISO you're correct, the 80D is a bit special there. It's actually OK even at ISO100 for astro use it seems. However, i still think it's important to increase the ISO to get the signal above the noise floor if you're unable to do so by increasing exposure (correct me if i'm wrong). I had a quick go at your pic trying to separate the soul. Far from perfect processing, but the soul is for sure there! Did you check if your scope/camera/filter had dew on it? If not, then it looks like something might have gone wrong with your flat frames, causing processing to be more difficult. If both flats look fine and no dew on the scope, then i hope someone else can explain the uneven color and brightness. Attempted to just align colors: Tried to correct the surrounding colors somewhat and pull out the soul:

Sure! These are at least some of my images so far where I've used the Polemaster only, or for Ha and/or L data. Cygnus HaRGB. Polemaster for Ha, RGB from 550D: Fireworks Galaxy LRGB - L from PM, RGB from 550D: M63 Sunflower Galaxy LRGB - L from PM, RGB from 550D: M51 LRGB - L from Polemaster RGB from 550D: M13 LRGB - L from Polemaster, RGB from 550D: Bubble Nebula LRGB - Polemaster only: Eagle nebula HaRGB - Polemaster only: NGC 2841 LRGB - L from Polemaster, RGB from 550D: NGC 2903 LRGB - L from Polemaster, RGB from 550D: NGC 2403 LRGB - L from Polemaster, RGB from 550D:

cbbella: That adapter appears to be a finderscope to C mount adapter, not a finderscope to 1.25" adapter. To use it with either the Polemaster or QHY5L, simply remove the already attached C/CS mount to 1.25" adapter (C/CS mount lens for the Polemaster) and screw camera on directly. You won't be able to use any 1.25" filters together with that adapter, but neither is it needed (you will get bloated stars without the IR filter on the finderscope, but this will not affect guiding accuracy). iapa: Glad to hear you got it working! :)

Hi, Sorry for the late response. I'm not sure if i understand exactly what you mean. Are you talking about the inner threads in front of the 1.25" filter? I'm trying to remember where I've bought it, but I honestly can't remember for sure. I've only ever bought two 1.25" IR/UV filters, one together with a webcam, and one from e-bay with the 1.25" adapter for the Polemaster.

Michael, sorry for the late response. Yes this is with the most aggressive hysteresis setting, not the default 2 degrees. The problem is that the temperature keeps dropping for a while after peltier is turned off, causing it to wait for a while before turning on the peltier again. This again causes the temp to raise for a while after peltier is turned on. So even though the controller tries to keep it within +/- 1 degree, it swings with +/- 3-5 degrees at best. Allinthehead, I tried with the filter in place and didn't seem to get any reflection issues. However, I wasn't able to test much as even with a heater on the filter fogged up. I haven't quite given up yet though, and it does appear the best option is to leave the filter in place and have a bit more heating on the filter itself. A heater strip like that won't really work though as it would heat up the camera body and not the front filter, but I'll see if i can make something that will fit somehow.

I really love everything about how this image turned out, great job!