Fegato

I don’t believe that’s true about bit depth in terms of anything a human can perceive once stacking has taken place. See e.g

You are too modest - that's very nicely done!

Well, I guess one step at a time, but if you are keen on astrophotography, automation sort of becomes inevitable... plate-solving is where software uses the stars to precisely point your scope at a particular position / target. A pre-requisite is that you have your mount attached to a computer (Windows is pretty much standard, as some components only work on Windows) - there'll be explanations of how to do this in your mount documentation and/or elsewhere on the net if you want to go down that route.

I use NINA for acquisition - it's free, and among many other things, it will frame a mosaic for you. And then it can plate solve (via ASTAP) in order to get precise positioning. I'd recommend it. For mosaic production (and everything else post acquisition), I use Pixinsight - obviously that costs money and has a learning curve, so may or may not be for you.

thanks Roy!

Thanks Peter. Yes, I spotted it on Aladin when framing the mosaic, fairly faint - but amazing what you can pull out with starless processing these days!

I spotted this on a panel of a Veil Nebula mosaic that I haven't yet been able to complete due to our weather, and thought it deserved its own image! Beverly Turner Lynds catalogued this as LDN846, possibly including some of the wider dust around it, as her dimensions seems to cover most of this image. I can't find any other pictures that focus on this object, just one or two where you can spot it in the corner of a wide field Veil Nebula image, but maybe there are some out there I don't know? Any offers? Or any idea what's going on here - just a bit of buffeted dust I guess? Taken with RASA 11v2 on CEM120 and ASI2400MC Pro. 89 x 30s.

This is supernova remnant SNR G65.3+57, which sits in Cygnus, pretty much right in the middle of the summer triangle. It's very faint, and in the middle of a dense starfield, so a bit tricky. If you're interested in more information about this object, there's a bit of commentary on my astrobin here - https://astrob.in/1y5wqw/0/ This is a 2 panel mosaic. I started it in July, and by last week was worried it would never get finished, given the weather we've been having. But last night was good enough to get the second panel completed. Details: RASA 11v2 on CEM120, ASI2400MC Pro, 135 x 30s across 2 panels for broadband stars, 7h 49m across 2 panels with IDAS NBZ dual narrowband filter

No worries - enjoy the processing!

I think it's worth considering cropping just the "dithered edges" out right at the beginning (obviously "artistic cropping" is probably best done at the end!). Some post processing can be affected by these edges (or so I've read), like background extraction and maybe colour processing. Maybe not a big deal, but as I say, that's what I've read. Certainly mosaic stitching can get messy without tight edges, when you get to that.

This square pattern can be caused by star removal, particularly in a very heavy star fields (like the Veil). If you are using StarXTerminator, click the box that says "Large Overlap" and all should be well! (it takes a bit longer, but works for me - I always use this now when removing dense star fields) PS looks like that image needs a bit of trimming before you go much further, due dithering I guess?

as above, I've found that https://www.astrobuysell.com/uk/ works well

This was my first effort in 2018, a single frame taken with a Fuji XT-20 attached to a Celestron 8 Edge HD on an Evo mount. I guess things have come a fair way since then and also a lot of money has been spent...

Very nice data actually! - here's my effort with it. I use Pixinsight, so the main thing here was using range masks to control the bright parts of the nebula while stretching the dimmer areas. Also processed starless using StarXTerminator.

No problem with that image - the bright parts of M27 are under 10% of the available exposure, so it's just a question of managing the stretch. I'll have a little go at it.

I'd be surprised if 3 minutes was too long at F/7 or F/11... not sure which scope you were using? ..and as Alan says, would be useful to know Gain setting. M27 is quite bright, but not so much that it easily blows out. However, if you try and get the outer areas to come out in stretching, the centre does tend to blow out, so careful use of masks is probably needed to achieve that. Can you post your un-processed integrated image?

Kudos to those of you that juggle astronomy with work, I couldn't have done that - I retired early, and only started astronomy after this and a move to dark skies in Wales. Really I need a full 8 hours sleep, and I don't like the cold much either, so my initial observing phase was limited to winter evenings, and I often found it a struggle. I gradually moved to imaging, and have got to the stage where this is my focus and I have it fully automated (after initial set up - I have a wheel out rig, that I can cover for a few days if needed). Having said that, I often don't sleep that well when the rig is in action outside, particularly after a late evening getting set up, although I'm getting better at it. Despite my focus on imaging, there is certainly something special about being out there in the dark observing - so when the nights draw in I try and get out with binoculars for at least half an hour or so when the skies are clear. I find this relaxing and enjoyable - no fighting equipment, no feeling I have to stay outside to make the most of having spent all that time setting up. Anyway, look after your health Paz and everyone else, that's the most important thing.

I've had a quick go, nothing better than Alan has produced above. Background extraction is a bit of a pain with an image like this as there's so much nebulosity, so I didn't bother, and the end results shows there is a bit of a gradient reducing from right to left! Anyway, a couple of observations: 1. There's a fair amount of noise. You didn't describe your equipment (including filter(s)), exposures and sky conditions - would be interesting to know. Looking at the data, I would guess maybe the exposures were fairly long (stars a bit blown out here and there), but you do need more data? 2. As Alan says - there is a bit of a darkish band across the bottom. If you stretch very hard, there's maybe one across the middle too, but not totally sure. It's difficult to be sure when there is all that dark stuff following a similar path. If it is an artifact of some sort, I don't know what could cause this - assume you have no obstructions in the light path? Anyway, best take some other images and see if it repeats before getting too worried about it.

My rig wheels out and is quite quick to set up, and then fully automated. I have the telegizmos lightweight covers, so can leave it out a few days when there are multiple clear nights. It does somewhat detach you from it all, but I try and get out with my bins when I can to keep engaged with the sky!

Thanks Alan. Yes, it's quite hard to get the stars colourful with the RASA and a "long" 30 second broadband exposure! I just tend to push the saturation a little bit after separating the stars from the image. I know many use MaskedStretch or arcsinh, but I find these give me star profiles that I don't like - and I'd rather have a nice star profile and less colour tbh. I have tried GHS a bit, but not much - I'll give it a go in the way you describe and see how that goes.

Thanks Bargy! Yes, I got the method from an Adam Block youtube post, and it's really helped a lot. I'm normally trying to pull out dusty detail, and it's so hard to know what you're looking at with all those stars. I'd got to the point that I just gave up and used ABE on some images, which never worked that well.

Thanks Roy! I had mixed results with mosaics until I started using the PI Mosaic scripts - I've found these to work really well, and as mentioned above, I've learnt a bit more about some of the options available which has helped too. This has all been necessary learning, as I use mosaics a lot - mostly because I don't rotate my camera at all, so often need them in order to get a subject framed properly (downside of RASA - camera rotation is prevented by need to manage tilt, upside of RASA - 2 frame mosaic doesn't take too much time!).

Captured this data in January, as I thought it would be a fun challenge to try and put together a wide field covering the whole Orion's Belt area. It's a 4 panel mosaic. However, my first attempts at processing this were not successful - issues with gradients across the different panels (caused by the vignetting I suffer from rather than LP), exacerbated by my desire to stretch this quite hard to pull out the dusty details all over the frame, made the end result a bit of a mess. Since then I've learned a bit more about the options in PI's PhotometricMosaic script, as well as discovering a starless technique with DBE which I now use all the time - so I've had a go at re-processing, which has been more successful. The other main challenges were (a) using masks in some of the stretches to keep the brighter areas under control and (b) getting the bright belt stars to fit back in reasonably naturally after starless processing of the rest. I've also attached a crop showing just the more often imaged Horsehead / Flame nebulae area. RASA 11 v2 on CEM120, ASI2400MC Pro (no filters), total 3h 27m across the four panels, captured on 23rd and 25th January.

Yes that's looking good - excellent! NB I have played with the Gradient settings on PhotometricMosaic at times, although with a big mosaic like this, it's sometimes harder to get everything perfect. Most often I'm just turning off "target image" if I have strange gradients (blotches!) along the edges, as this will potentially propagate them across the target image. And meant to ask before, just checking - are you running DBE on each panel before putting the mosaic together? That is recommended.

Couple of points: 1. I used to suffer a from pinched stars like this. This tutorial https://www.lightvortexastronomy.com/tutorial-preparing-a-mosaic.html explains use of Shrink Radius setting to try and help sort the problem. But it also has a method to cut the offending star out of one of the images using PixelMath to avoid the problem, which I used successfully. I assume this only works with the Overlay method of merging though. 2. However, now I always use the Mosaic scripts - MosaicByCoordinates and PhotometricMosaic. I've not had this problem at all - these scripts work really well and I would recommend trying them as an alternative to the PI processes.