Fegato

thanks Carole! Looks a bit 'soft' now I look at it again, but I guess it's pretty faint and stretched quite hard, so not easy to get clear details, and conditions weren't brilliant on either night. Anyway, at least it's one off my list of "in progress" targets that I can't seem to get finished!

LBN 923 sits on the border of Orion and Eridanus. Molecular clouds, dark nebulae and HII areas are topped with the bright reflection nebula NGC 1788 aka vdB 33. Not so often imaged due to its more famous neighbours, but there are still plenty of images around, including a very nice recent IoD on Astrobin. I shot some Ha (dual narrowband) earlier in January when the moon was up, and was looking glumly at the forecast for the coming new moon period when a little break in the weather appeared last night and gave me 3 hours or so before the moon came up. The session was close to disaster, as I had to get it going quickly and dash out for a couple of hours. Needless to say, for the first time in months I had major connection issues - nothing would connect to the mini PC on my tripod tray. I ended up running around pulling wires out left right and centre, and in the end I assumed that my OTA mounted Powerbox had given up the ghost, causing issues with power distribution, as well as causing all the USB from my mount hub to fail. I gave up on dew control, replugged the cameras into the mount USB, got it all going, and rushed off. When I came back, I realised that the guide camera had disconnected before it even got going. Anyway - I got 2 hours of data, and if nothing else, this shows that guiding at 30s with my rig is somewhat unnecessary (albeit I lost all my dithering too). Of course - this morning I take a look at the rig, and realise that the power feed into the mount had become unplugged... in my hurry, I forgot to check the obvious! What a berk! More haste less speed as they say... Anyway, here it is - broadband enhanced with Ha / Hb (fed the Ha into red channel and blue channel at 20% of red). RASA 11 v2 on CEM120, ASI2400MC Pro, 236 x 30s plus 104 x 60s (NBZ dual narrowband filter)

sorry - should have added, if you weren't aware (not sure), Aurora panels are a particular make of flat panel by Gerd Neumann - see https://www.gerdneumann.net/english/astrofotografie-parts-astrophotography/aurora-flatfield-panels/uebersicht-aurora-flatfield-panels-overview.html

Well, your flat looks OK, but whether the colour side of it is right I don't know. As pipnina says, laptop screens may not work that well. For a Redcat 51, I assume the smallest Aurora panel would be fine, which is not too costly. You will probably need to buy one or two of his "filters" too, as the panels are not dimmable, and this is the only way of dimming the light a bit (more of an issue with broadband flats, although at F/2.2 I use one of these for my dual narrowband flats too). As I said - I did have some success with a tracing panel previously, so you could pick up an A4 one of these a bit cheaper and try that. I can't see any obvious signs of vignetting, and I guess you shouldn't have any visible with a 44mm image circle. So I think this is just about the OSC bayer filter and an effect that does happen with narrowband filters. I'm not an expert - you can probably find articles and posts about this online. Perhaps the signal is very slight weaker around the edges, and the red signal has less intensity anyway, and this is the end result (albeit your integration should be taking account of the different channel intensities - certainly Pixinsight does this). But as above, I do get this sort of red / green issue too in narrowband. I suspect you'll still see it even with a better flat panel, and you just have to use gradient removal techniques to get rid of it.

I think with a narrowband filter and OSC something like this is almost to be expected. I do have vignetting to deal with, but also tend to get a red to green gradient across the frame when using a dual narrowband filter which has to be removed using gradient removal techniques (DBE in Pixinsight for me). Maybe you have some vignetting here as part of that too ( I do too). It is worth trying to get good flats certainly... never tried the laptop method. I did have some success with tracing panels, but when I got a RASA 11, I invested in an Aurora Panel which works well for me. Can you post a sub and a calibrated sub and your master flat? Might help to see if any issues there...

Thanks Dave, yes I think the other one needs a bit more contrast - a bit washed out I think.

I spotted this as a good target for later on in the night at this time of year. It's a very large PN at around 20' diameter, and one of the closest to us at around 1200 light years. It is faint though, and was only discovered from the Palomar Survey plates in 1980. Current equipment makes it very accessible though. I also found that I had 48 minutes of exposures from two years ago, which I had totally forgotten about. Lots was added to this with the NBZ filter, totalling 7h 15', which I think is as much as I've ever shot on one panel. I also took about 50' worth of broadband exposures for the stars. Of course when processed, as ever with the RASA, a dusty backdrop appeared. So here are two versions, one close-up - narrowband with RGB stars, and one wide field - broadband with enhanced narrowband for the PN. I've also attached an annotated version which highlights the various PGC galaxies as well Quasars from the "Million Quasars" catalog. I hadn't realised this had appeared in Pixinsight, and it's a bit of fun trawling around and looking these up. Only looked at a few, but the first couple I looked up were estimated at 8 and 10 billion light years distant! RASA 11v2 on CEM120, ASI2400MC Pro, 217 x 120s (NBZ filter), 151 x 20s (no filter)

Nice one! The most often used method with M42 on PI is to use HDR processing. In very simple terms, as well as your main stack, you take a set of short exposures as well. Both sets are pre-processed / integrated separately, and combined using HDRComposition. Then later on in post-processing, after main stretching, you use HDRMultiscaleTransform to bring out the detail in the saturated core. For the short exposures - run some test exposures to make sure that you can see all the stars (particularly the trapezium) right in the core. For the longer ones, you'll probably see the core a bit blown out, but that's fine. For me with a very fast RASA, it was 20s (long) and 2s (short)! If you're at F/7, maybe 180s and 20s might be roughly equivalent. With regard to filters - Orion is bright - you don't need a narrowband filter to take a great image, in fact for me, you lose a lot, particularly if you have darkish skies, as there's a lot of dust to be found. However, if your LP is really high I guess that's another matter. You'll find tutorials on HDR processing in PI online. I tend to dislike youtube videos for learning, and learnt a lot of my basics through the tutorials on LightVortexAstronomy. These are a bit out of date now in places, and recently the website disappeared sadly. But there is a web archive currently available of the various pages, including one on HDR Processing - see the link in this thread: https://www.cloudynights.com/topic/905963-light-vortex-astronomycom/

I'm fairly relaxed about it all now I must admit. Some time back, I do remember heart being in mouth every time I got the rig out, but now I've got it so that I know what I'm doing and it mostly just seems to work (touch wood). I just roll it out a few yards plug in power and two ethernet cables, and then aim to polar align and calibrate the guider before astronomical darkness sets in, meaning I feel relaxed that no time is being lost. It's not quite like having an observatory, but as close as I can get (my wife is not keen on any more buildings, and anyway, I quite like having the rig stored indoors when not in use - it's so damp here). I think my main stress is sometimes overnight - I have everything automated, so if I risk leaving it going outside and I'm not 100% confident of the weather, I really don't sleep very well! Overall, I suppose being retired helps (time-wise), although I'm guessing there will be some age limit on my ability to nurse a 100kg + rig down two disability ramps through the bi-fold doors onto the patio!

well done - brilliant!

Nice ones, I think I prefer the first too. I don't think the RASA is overkill at all - it's great for pulling out the surrounding fainter dusty areas (although there comes a point where masking is required to stop the reflection area blowing out). I'm in the middle of an M45 myself with my RASA - a wider field 3 panel effort (full frame too), with the aim of showing all the surrounding dusty bits.... but it's been a bit of a marathon, going in since before Christmas, due to lack of clear sky time.

yes +1 to that - it does make a big difference to be able to do that when there's a risk of poor weather coming in and it's time for bed! I guess only any good if you're imaging at home and it's reasonably secure as you say. I can't cope with the cold for long, so I limit my visual observing to brief spells with bins at this time of year, and focus on automated imaging.

Well, as someone else said in a recent thread, my favourite is often my most recent (although not always!). But here are a couple: Firstly, M78 across Barnard's Loop to LDN1622 (sometimes horribly called the boogeyman nebula). Shot in February 2023, but just re-processed, as my original version had some nasty unresolved gradient issues as well as looking a bit washed out. Secondly, a 6 panel mosaic of the Veil Nebula with surrounding dust. I posted this at the time, but have since added some OIII data to just enhance this in the SNR itself, as it failed to come through very well in the purely broadband original.

Missed the clear night here on Saturday as I was away, which was a bit of a blow, but then it suddenly went clear from just after 10pm last night. Shot this wondering if I could find some dust, but not really - just a bit of haze, which I think is largely real, and a couple of small bits of bright reflection if you look closely to the top left of the nebula. But mostly just a big pinky red Rosette really... RASA 11 on CEM120, ZWO ASI2400MC Pro, 251 x 30s over 2 panels. Edit: While the RASA should cope with a full frame sensor (with 50x50 filters when using), I should add that I suffer from vignetting (it's a long story), quite bad in the corners, and there's definitely some residue from that in this image with dusty looking arcs.

Nice one Göran! That does sound cold! We've got it "cold" for a bit now - it's forecast -3 tonight! Last night was our first full clear night here in W Wales since the summer... and I was away in London! Hopefully one or two more in the next few days. As for KN... I found an old paper referencing another PN called Kn 61, which includes this - "Originally found by Matthias Kronberger, a member of an amateur astronomy group known as the Deep Sky Hunters (DSH)" https://phys.org/news/2011-07-discovery-planetary-nebula.html

yes, that's why I thought maybe they've designed their own built-in camera, width less than the ZWOs etc.

Yeah I reckon a smaller RASA with a built in camera (hopefully perfectly backspaced and aligned, avoiding all that faffing around with image train).

I think "push a button" is a long way off. After all, we'd all want a different button! (take the same base data, and we all produce and want to produce something slightly different) Anyway - BlurX does a marvellous job of leaving all the tiny galaxies alone, as does StarX. I'm in the middle of a hell of job trying to mask these all before some heavy stretching to avoid super bright / saturated galaxy blobs all over the place! I need GalaxyX please....

It's a lovely image - quite a mesmerising colour certainly! There's lots of luminosity and depth to the whole thing too, so I'm not complaining. My recent effort on this looks dull by comparison, that's for sure. I guess you can have "too intense" if things are stretched or saturated so much that noise or artifacts start dominating. But mostly I think it's just "more intense" and "less intense". I often like images at both extremes - they show different facets of the scene.

thanks Charles! Yes HDRMT is a nice tool to have available and does usually do a good job, just a case of getting the balance right with the layers (bit subjective I guess, but I don't like it when it makes things too "flat")

thanks Chris! Yes, I could try adding some more, but I normally think an hour with the RASA is enough when shooting broadband, not least because I'm always impatient to move onto other targets!

I'd imaged NGC281, aka the Pacman Nebula, with a dual narrowband filter a couple of times in past years, but was prompted to add it to my list of broadband targets this autumn after spotting an image showing plenty of dust around a few weeks back (which I can't credit because I can't find it now, sorry). @cfinn beat me to it, with his excellent image posted a few days ago, but I've managed to get mine done now and here it is. I captured the data on Saturday. It was a rare clear night, but the wind from one of the weekend storms was strong - 20mph with gusts over 35mph. A bit foolhardy to try and image in those conditions... but sometimes beggars can't be choosers, so I risked it. I sat on the target for much longer than I normally would as I knew lots of subs would be wasted. Guiding was often at 2" RMS, and I had plenty of in-sub dithering! Anyway, the rig stayed upright, and with 30 second exposures, I managed to get just over 1 in 3 that were usable. Processing was a bit of a battle, mainly due to me stretching so hard to really push the dust (maybe I've pushed too far?). Firstly trying to control the brightness of the Pacman while bringing out the dust was tricky - in the end, despite a lot of masking, I resorted to applying PI's HDRMultiscaleTransform on the nebula, which worked quite well. And secondly I had a lot of colour balance issues. Red channel seemed very weak after stretching, even after careful background neutralisation and colour calibration, so I had to push it a bit. Not sure if my dust hasn't ended up a bit orange. I was interested to spot the little areas of reflection nebulosity and perhaps star forming areas above the Pacman in this image. One of the reflection areas is catalogued as DG6. I found an image on Astrobin of DG6 which pointed out that the area of dust around it looked a bit like a horse (lots of horses up there it seems!). This image is over 10 years old, and rather nice I think - bright colourful stars shimmering with just a faint ghostly horse visible in the background https://astrob.in/60471/0/. I attach a crop of my horse too - a bit puffy and unsubtle in comparison. Possibly this star removal business encourages us to go too far sometimes... Anyway - captured with RASA 11 v2 on CEM120, ASI2400MC Pro, 120 x 30s (out of 302 attempted)

thanks Olly & Göran! Seems to have become a thing of mine going for these sort of targets in broadband - a Pacman to come shortly. Lucky with the dark skies I guess, if not the clear ones!

I'm just processing my attempt at this now. Interestingly, that dark rift does actually seem to be full of dust - I can see that before doing much other processing. So while a dark contrast would be more dramatic, it's possibly not exactly what's there

You were probably better off in the cloud! It was clear here in SW Wales for a a few hours, but 20mph wind with c 36mph gusts. My rig was out and my guiding was often at 2" RMS, and although it's very heavy, I did wonder about it blowing over! I only shoot 30s subs so I'm hoping I might get 1 in 3 usable, but we'll see. My best bet would probably be to enter the Animation Challenge with an animation of my dancing and elongating stars, but I think that challenge is over!