gorann

This is a wide-field view taken with my dual-RASA 8 rig with ASI2600MC and an NBZ (Ha+Oiii) filter. To this I have added Ha and RGB data I have from my dual-Esprit rig. For much of the other rather striking but fairly weak nebulosity in this image I have not found any names / designations. RASA8 data collected 31 Jan 2022 (48 x 5 min). Esprit 150 (RGB) and Esprit 100 (Ha) was collected 29 Nov 2019 (90 x 10 min). So totally 19 hours. Processed in PS and PI. Cheers, Göran

This image has evolved to something very nice! Regarding the smooth areas around removed stars, I had the same effect with PS Star Xterminator AI version 5 but it is gone from the new AI version 7, but that one introduces other artifacts that I found can be treated with a light touch of the Dust & Scratches filter in PS.

I can only find one or two images of each of these neighbouring Sharpless catalogue objects, and none with them together. In the upper left corner the open star cluster NGC1857 can be seen, and near the bottom is the small Ha patch known as PK169-001 of IC2020 (the position of the latter appears misplaced by the attached Astrobin plate solve), once misidentified as a planetary nebula, see http://simbad.u-strasbg.fr/simbad/sim-id?Ident=PK%20169-00%201%20 Imaged during one night with my dual-RASA rig. No moon up so I could go rather deep with the NBZ (Ha+Oiii) filter. Captured on the night 30-31 Jan 2022 in my home obsy with two RASA 8 and ASI2600MC (IDAS NBZ filter, gain 100, offset 30, -15°C) on a Mesu 200 mount. 193 x 5 min, so 16 hours. Processed in PI and PS, including Star Xterminator to make a starless image to stretch the nebulosity before bringing the stars back. Cheers, Göran

Excellent M101! For the dark rings you often get around stars when adding them to a starless version (I use Star Xterminator), I came up with a method that I use in PS. I select all the stars (Select -> Color range, putting the selection-eyedropper in a medium bright star and put the Fuzziness slider rather high). Then I expand the selection (usually around 4-5 pixels) to cover the stars and the dark rings (see image), and feather it (1 pixel). I then use curves on the selection to just lightly make it brighter in the lower end of the histogram. That will effectively remove the dark rings (you may have to do a few attempt with different expansions).

I must have missed it but now I had a look. Great witchhead Tom! You really managed to capture a lot of that elusive Ha.

Yes, very nicely shinig dust Tom! I see some middle ear bones in there and of course a bird head. Would have been really sad if this had ended up in the crop bin. Looking forward to the Witch next.

Yes, I just saw the same things and expanded a bit on my comment.😁

I have to say that the Artesky one is really good looking but then I saw the nobs. How do you get a grip on something looking that smooth? Design over practicallity? Reminds me of a fancy coffee machine and when I see the latitude scale I realize it is only meant for southern Europe.

I would not put one of these in my obsies, but very tempting for travel, once they get properly reviewed.

Maybe this one has been noted in the thread, but if not I just had an email-ad from Artesky of another harmonic drive mount at a very reasonable price: https://www.telescopi-artesky.it/it/artesky/harmonic-drive/5516-montatura-harmonic-drive-bh17-h-8055517139745.html

Thanks Michael! The best of luck with your sky! Not much luck here right now...

I would also stear away from the ASI294MM. It is the old generation of CMOS with amp glow and has some issues. Maybe @wimvb can chip in here.

Thanks a lot Rodd! Maybe Santa is in zombie disguise while in space?

I have not seen many wide field images of Sh2-274 and the surrounding nebulosity, so I thought is could be an interesting target for my dual-RASA rig. No moon up most of the night, so no moon light and gradients to worry about. Still, I decided to go for a NBZ-filtered image (Ha and Oiii) rather than RGB to get more punch in the Ha and Oiii. Sh2-274 is known as the Medusa Nebula, but to me, especially with all the Ha shining in this image, it reminds me of Santa Claus. It was imaged exactly one month after Christmas so fortunately for us he has 11 month to return😉 So, imaged on the night 24-25 Jan 2022 with two RASA 8 and ASI2600MC with IDAS NBZ filter. 145 x 5 min (=12.1 hours) at gain 100, offset 30, -15°C. The annotated image is a screen grab from my Astrobin. I also added a close up since the image shows quite a lot of detail for being 400 mm focal length. Cheers & CS, Göran

I do the same as Olly when I stretch in PS. In fact almost every stretch I do has one or more pinned points on the curve so I can get the curve shape I need and seletively stretch the part of the histogram that needs stretching. No idea how one could live without them, but then I have never stretched an image in PI.

You are not alone but you finally got it Rodd! It is the username I use for everything and it was once given to me about 26 years ago by the university I still work for. I assume they had other Gorans employed so the added the first letter of my last name. Sticking to it helps me to at least remember my username on different systems and platforms. Unfortunately, I also have to remember a plethora of passwords....

An outstanding image Rodd! Love the details.

Absolutely beautiful! That camp fire aided to make that lovely transition as you say, and brought one more colour to lift the image.

Great images Rodd! I agree with Wim that a bit of SCNRgreen could help the second one to be the winner. Amazing how much more detail can be seen in the core of M33 compared to M31. I assume it means that the center of M31 is much hotter.

My feeling is that blue can help equally well as green with the depth of an NB image, so I rather go for red, yellow and blue, than red, green and blue. But that is me.

Like them both a lot Dave! Both have excellent qualities. But personally I never really liked green in AP (just a hang-up I guess) and I am not great fan of magenta either, so it made me wonder what a mix of your images would look like, so I made a 50:50 mix. Hope you forgive me for messing with them, but I think it is kind of nice looking. No idea what the colour patette should be called. Cheers, Göran

The Witch Head is a very faint reflection nebula lit up by Rigel in Orion so Ha will only help you to add the faint Ha clouds near it (which @ollypenrice talked about) but not detect anything of the nebula itself, since it does not emit Ha. So, the Witch Head is all about darkness and a moderately light polluted sky can probably be compensated by a lot of integration time. But pure RGB objects like this one cannot be done in light polluted skies with NB filters, since there is very little NB signal in there. However, you do not need much of a kit if you get to a dark site, so well worth a trip out of your urban garden. Up here at 60° North it is a bit too close to the horizon, but I once captured it on one short night with just a light traveling kit on Lizard Island way out on the Great Barrier Reef (so Bortle 1). An ASI071 and a Canon 300mm lens on a SW Star Adventurer and a dark sky was all the Witch needed. Cheers, Göran

I would say it looks very promising Damien! In the end my cheap Chinese scopes and cameras could very well be run over by your smooth Japanese and UK machinery, but maybe the Swedish Bortle will save me🤣

rather good match with the human eye spectral sensitivity (http://www.yorku.ca/eye/photopik.htm), as expected since we evolved under this star. But is is striking how much of the red and IR part of the spectrum our eye misses.

Thanks for that @vlaiv, it does explain why we have a sun that gives us here on earth sunlight with what we call a continuous spectrum (maybe with those dips you point out - or does it?).