Xiga

It might cover the nebula (i haven't checked) but i doubt it would get in all the similar surroundings in RBA's version. If you use the 180mm lens, however, then you will have to register all the nice Tak data to it, and then you lose your image scale and all that nice close-up detail. Rather, i would just put the Nikon onto the Tak and see how many panels it would take to cover the whole area. You might be able to squeeze it all in in 4 panels. With 180mm of aperture, 2 hrs per panel would probably do it. With these long nights, you could do it in a single night. Well, if we ever get a clear night that is!

This has the makings of a spectacular image Adam, once complete. Keep going! I'm usually not into inverted images much, but i really like this one. It reminds me of a tardigrade! You're not going to thank me for this Adam (you can feel a 'but' coming can't you?!)....but, once you are done with this as a Bi-Colour image, you should consider capturing some RGB as well, and extending the Fov. Your Nikon would be perfect for this. There is plenty of interesting stuff going on around the Spaghetti Nebula in broadband light, so it would make for a very interesting (and different) image to the Bi-Colour version. The idea being that it would essentially be a base broadband image, but just with the Ha and Oiii from the Spaghetti Nebula blended in to really make it stand out. Have a look at RBA's image below to give you an idea (note, he didn't shoot any Oiii). http://www.deepskycolors.com/archive/2011/12/08/simeis-147-and-surroundings.html

Wow Richard, that's some improvement over the original, and there was nothing wrong with that either! You've managed to make it brighter, and, less noisy at the same time, no mean feat! Care to say what you did differently this time? I see you down-sampled the image too. I think this was a wise choice. The image loses nothing in the process, and it no doubt helped hide some of the noise too. 👍

Lovely image Mr_42tr0nomy! Like you, i too have found Topaz Denoise AI to be very useful, in certain circumstances, i.e mainly with NB. I have found, with the right settings, it does an absolutely amazing job at cleaning up the grain that is inherent with NB data (but not so much much with Broadband data). So much so, in fact, that it is now an integral part of my NB workflow. ps - Aside from all of this, great processing btw! The stars are nice and small, and i love the colour balance you've achieved.

Very nice Gina. I'm amazed you got the squid with so little exposure so well done! One small piece of CC, the image looks a bit green on my phone. Perhaps a bit of SCNR Green or HLVG could be worth a shot?

Also, instead of using Bend Mode Lighten with the Oiii, another method worth trying would be to use Screen but only apply a very small amount, say something in the region of around 15%. Basically, the minimum amount that lets through the added details not present in the Ha. Then use the usual layer mask to only apply it to the nebula.

Here's what i would do Adam: 1. Get the stretch of the Ha and Oiii as close as possible. From the versions above it seems like they are probably close enough. 2. Add the Oiii on top of the Ha in PS in blend mode Lighten. This will add some details to the inner shell as well as the all-important outer-shell. 3. Use a layer mask to only apply this to just the crescent and outer-shell. Flatten and save this as your Lum. Now combine it with your Colour just as before. If the all-white stars bother you, you could always create an interim HOO (or Synthesized Gree) image using the Ha and Oiii images with their stars intact. This will get you some star colour. Then you can apply it over your combined Lum+Colour image in Blend Mode Color using a star mask, so only the star colours are affected. I did the above on your jpeg, plus i applied a couple of passes of star reduction from Images Plus (but not on the crescent itself). Only spent 20 mins and it's a bit of a bodge job, but hopefully you find it useful.

Hi Adrian I too have played around with trying to add stars back in over a starless layer and i feel your pain, it's really not easy to do well. I've had most success doing it on galaxy images, where you have a central contained object of interest, surrounded by background sky and stars. For images of extended nebulae, it's much, much harder to get right. I also don't like my images to have too much star reduction, so for these types of images i've reverted to good old star reduction, but using the one from Images Plus. Mike Unsold has made IP free to use now, and the star reduction process is currently the only thing i use it for. I've found it to be much better than any other type of star reduction i've tried to date (be it Carboni's or Annie's versions, or the minimum filter in PS). The default settings work quite well, so it's a 1-click operation 😀 Here's how i go about it: 1. Open your image in IP and choose Special Functions->Star Size, Halo, Shape Reduction... 2. Hit Apply! 3. Press Done and Save your Image as a New Image. 4. Close, Re-Open the New Image and Repeat. (I'm not familiar with the UI so i'm sure there is an easy way to do 2 passes without having to close and re-open. If anyone knows please let me know!) Often 1 pass is not quite enough, so it's worth running 2 or more passes, until you find the one you think has gone just too far, and then apply a lower opacity to it in PS. The routine also seems to apply some sharpening, which you may or may not like (i personally like it). If not, it wouldn't be too hard to mask out the areas of highest contrast. The stars are tightened up quite a bit too, they certainly come out a lot better than Carboni's or Annie's ones. However, if you find they are just a little too tight for your liking, then i've found that running Carboni's 'Less Crunchy More Fuzzy' routine over it at an opacity of ~40-50% often recovers that. Anyhoo, i ran 3 passes followed by Carboni's Less Crunchy on your Jpg. The result is below, just in case you find this useful. HTH.

Quite right! I just assumed the Platesolving would pick up on most, but it actually only highlights a very small number. Spent a bit more time eyeballing it at 100% and there are actually loads sprinkled throughout. It's quite fun hunting around looking for them 🧐

Fantastic mosaic Richard. And a great idea to make use of the old Ha data too. Glad you got the diffraction artefacts sorted. The stars look even more awesome now. The wee galaxy (NGC 7379) hiding at middle left was a joy to find 😀

Been meaning to do a starless Ha version of this, and finally got around to doing it tonight. Starnet really is amazing i must say. It takes all the work fun out of it! 😋 Very little processing on this. Just a Levels adjustment followed by a bit of NR in the darker areas. At only 108 mins per panel, it's still quite noisy, so i downscaled it to 50%.

Thanks Noddy. That made me laugh i have to say 😁 Thanks Richard. APP really is amazing for doing mosaics. I know you use it to, so i can't wait to see what you have in store for us. FWIW, i used LNC settings of 2 Degrees and 10 Iterations for this one. Thanks Ian 😀

That's turned out lovely Brendan. Subdued but still with plenty of colour, i really like that. Out of curiosity, do you downscale your images? I notice it's not possible to zoom in. ps - Do you know what the little blue thing is at left of centre? A Planetary Nebula of some kind maybe?

Ran a short 100 min Ha stack through Denoise AI as an example. These are just jpg screenshots, but they should be good enough. Original stack: With some Denoise AI. Notice the harsh edges to some of the stars, especially the very smallest ones: Layer mask applied. Inverted version of the original image: Levels adjustment to the layer mask: Final version. Notice the star edges are now much better. Less NR has also been applied to the high signal areas. If you want more NR, then just use a higher setting in DNAI.

What i like to do is, intentionally use a bit too much NR in Topaz Denoise ai. Then bring it into PS, layer it on top of the Pre-DNAI version and apply a layer mask to dial the effect back a good bit. The layer mask is just an inverted copy of the original image itself, with a Levels adjustment to clip the white point and also bring the black point up to just past the heel of the curve, enough to make all the stars nice and black. This way, the stars are protected, and the brightest parts of the image won't have as much NR being applied. Topaz does tighten up the stars quite a bit. You might like how it looks, or you might not, so it'll be up to you to decide if you want to fully protect them or not. There's always the Opacity slider too 😀 Personally, i like a certain amount of the tighter stars it produces. It can give the appearance of having used Deconvolution. Certainly the really teeny tiniest stars will need some protecting though, as they will almost surely end up looking like artefacts if neglected. Now that i think about it, i may have got the order wrong above. I can't recall if i do Denoise ai then starnet, or the other way around, so try it both ways and just go with whichever one gives you the cleaner result. As for the Spot Healing brush, there's not much i can add really. I just adjust the size of the brush for each click (using the square brackets keys). Don't go any bigger than you need to. That's it really.

Thanks Alan! 🛸 Cheers Ant!

Ah yes, makes sense now. It's been a while since I last looked at J.P Metsavainio's Tonemapping guide, but it's been around a while now so there are parts of it that can be improved upon imho. Have a go at this rough workflow... Crop all your data at the beginning, right after you've stretched and saved them. Layer them all up in PS, then crop, then save each one off individually so they are all still aligned and cropped equally. Throw the Oiii data into Topaz Denoise AI. Turn down the sharpness to zero and experiment with the amount of NR, e.g somewhere between 5 and 15 is usually good. Save. Then use PS to convert it back to Grayscale. If the stars now have some artefacts around them, which is common, then use a layer mask (of the image itself, with contrast boosted) which should fix them. Now run starnet on it, followed by some spot healing brush if needs be. Doing it this way, you should end up with a much cleaner tonemap, without as much reliance on then having to blur the data. HTH.

Cracking image Adam. That's a lot of nebulosity, and i really love the detail in the dark dust! Something looks off with the Oiii data though, it looks too soft to my eye. I went back and had a look at my own Oiii stack (done in APP) of this area from a couple of years ago, which had a similar amount of exposure (4 hrs) but mine was shot with the Nikon D5300. I quickly ran it through Topaz Denoise AI and then starnet, then resized it in PS to roughly match yours. No sharpening or contrast enhancement was done. As you can see, it looks quite a bit sharper, which i wouldn't have thought was possible. How was your focus on the Oiii?

Many thanks John. Alas, i have hardly put an eyepiece in the telescope since i took up imaging some 4 years ago. I really should get back to doing some observing. Thank you Steve! Hard to believe it was 4 years ago now that your first book got me started on this journey. Thanks Spock!

Thanks Adam. At F6.3 and F4.5 i might be ok then. Hmm....

Thanks Paul. I'm more used to dealing with 2.7 hrs of data, rather than 27! This was easily the most I've ever put into an image so far.

Wow, this is stunning. Really needs to be seen on a monitor to fully appreciate just how good it is. I would have guessed this was taken with a much bigger scope than an 80ED. Now I want to have a go at this myself. Bravo!

Indeed 😂 Off-topic - i've been thinking of getting a 3.5nm Baader Ha filter, but in 1.25" size. I've been using 2" filters up to now. Do you think i could get away with a 1.25" one with this setup? Whether i'd be using the lens or the 80ED, the T2 filter drawer would always be directly connected to the Atik, so it might be ok i think? 🤔

Thanks Adam. The original plan was only to capture 60 mins for each Ha panel, with the goal being to aim for an achievable amount of total exposure (by my own modest standards) so i could actually produce a finished image this season. Once or twice i made a start on processing it, only for another clear night to present itself, so i kept going at it until the weather turned. I'm really glad i did now, having almost twice the Ha data per panel made a huge difference in the end. I have to say i really like the simplicity of this kind of imaging. I am able to just carry the whole rig down from the Attic, fully assembled, and be up and running in not much more than 30 mins. That's a lot quicker than with the 80ED, which i keep packed away. Another thing that really surprised me, imaging at this scale (8.4") once i polar align, i am actually able to just restore the previous calibration in Phd2 and not bother with re-calibrating. I would never have imagined that was possible, only i tried it one night when i was in a hurry to catch a quick hour between the clouds, and the guide graph was no different, always somewhere between 0.75" and 1.25" depending on the seeing. I kept this up for about 6 of the 9 sessions and it was always the same, so that was a nice surprise. Thanks mackiedlm 🙂

Thanks Dave and Ahmed for confirming. Just my geriatric phone to blame then! 😜 Ahmed, it's a prime lens, not a zoom one. Specifically it's a Tamron 135mm F2.8 Adaptall II lens. Being an Adaptall lens, you can attach different mounts, so to attach it to my optical train i picked up an M42 mount for it, plus another adapter known as a 'Russian Adapter', which converts from M42 to T2. You can see the full optical train below. I only found out after i got mine, but there is a supposedly better version out there. I think it's the SMC F2.5 version, so maybe look at that one instead. The one i have needs stopped down to be useable. The CA is way less in NB than in broadband though. I was using step-down rings as well, to avoid diffraction spikes, and for this the sweet spot seemed to be using a 30mm step-down ring (~F4.5) coupled with moving the aperture blade one half-stop between F2.8 and F4. I haven't tried it properly for broadband imaging, but i suspect i will need to close the aperture blades to F4 at best.