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Messier 57 is is just coming into a position for a decent look around 11 30 pm. IT is a colourful object and I thought it would give me a good target with which to practice my colour developing in PS/Lightroom. I have read so much about how to produce a LRGB image from the four stacked/calibrated luminance, red, blue and green images, a lot seems contradicatory and some, when followed, gave me colour yes, but not as we know it. I am sure a fair chunk must be put down to me. Anyway, I now have a work flow which gives me colour, sometimes resembling what other people have obtained. Progess of sorts.
This images is based on 114s subs at gain 139, offset 21.
L 39, R 20, G 20, B 19
Calibrated and stacked in DSS (flats, dark flats and darks)
Messier 57 Ring Nebula in Lyra
NASA: M57, or the Ring Nebula, is a planetary nebula, the glowing remains of a sun-like star. The tiny white dot in the centre of the nebula is the star’s hot core, called a white dwarf. M57 is about 2,000 light-years away in the constellation Lyra, and is best observed during August. Discovered by the French astronomer Antoine Darquier de Pellepoix in 1779, the Ring Nebula has an apparent magnitude of 8.8 and can be spotted with moderately sized telescopes.
Equipment: Celestron 9.25 XLT at F10, Skywatcher EQ6 Pro GEM, ZWO 1600MM Pro, ZWO EFW with ZWO LRGB filters, QHY5IIC guide camera on Skywatcher 9 x 50 finderscope, Celestron Focus Motor
Software: Ascom 6, Eqmod, Cartes du Ciel, AstroPhotography Tool, PHD2
I scrapped all the Oiii and Sii data I previously took during a full moon (about 15 hours worth) and retook it all when the moon was a bit smaller at 76%. Ha was taken during 98% and 67% moon. All the lights were taken on the following nights: 12th, 19th and 20th September 2019.
Integration times, all in 600s subs unbinned:
Ha = 28.33 hours
Oiii= = 5.67 hours
Sii = 5.67 hours
The Ha data is really nice, and unsurprisingly the Oiii and Sii is not as strong (or nice).
I'm missing that (vital) step in my processing routine of getting the Sii and Oiii properly stretched to match the Ha, before combining. I dont really know how to deal with the weaker data properly. Any pointers would be appreciated.
What I do currently:
All the data is loaded into APP into separate channels/sessions.
The data is stacked and registered against the best Ha sub
This produces individual stacks of Ha, Sii and Oiii that are all registered
Each channel is processed with DPP in APP and then saved as a 16bit TIFF
Each is opened in PS
Stars removed with AA and any remnants removed and tidied up
I then open a blank RGB document in PS
I paste Ha into Green, Sii into Red and Oiii into Blue
Adjust the selective colour settings to get 'Hubble palette'
Adjust levels, curves, saturation until looks ok
All the Ha Sii Oiii data is then combined together in a single 'super' stack in APP using quality weighted algorithm to create a 'luminance'
That luminance layer is adjusted using levels, curves, and NC tools such as local contrast enhancement and deep space noise reduction (using masks to apply as required)
The luminance is pasted onto the above colour layer, and incrementally added using gaussian blur
Cropped and saved.
Here it is anyway I haven't intended on any more exposure time for this one, but will consider it, if the expert opinion dictates otherwise!
THIS ITEM HAS NOW BEEN SOLD.
This listing is for my personal narrowband filters (Kayron from Light Vortex Astronomy). They are the Astrodon Hydrogen-Alpha (HA), Oxygen-III (OIII) and Sulphur-II (SII) 3nm 1.25" narrowband set. These are considered the highest-end narrowband filters money can buy, able to produce images of exceptional quality and incredible sharpness, cutting through a vast amount of light pollution. The 3nm variants featured here are fantastic for pulling out fine nebulous structures clearly above background. For more information, please see Astrodon's website:
Please note that these three filters together currently retail at just over £1,710 from UK suppliers, €2,180 from European suppliers or $1,690 from US suppliers. Payment is preferred via bank transfer but PayPal is OK with an extra 2.9% to cover PayPal fees. I'll cover postage to you via tracked Courier.
I welcome any questions you may have regarding this listing. Thank you for looking.
Hi guys, its me kronos, and i am about to purchase a new a new filter for my 5” and 8” scopes. I cant decide wether to buy a UHC or an oiii filter.
my budget it 70euros max
And i have settled between the uhc explore scientific
or the oiii explore scientific.
i am open to other suggestions in this price range
i am keen to observing more deep sky objects with better detail
Whichever filter i wont buy now, i will buy a better one in the future(for example if i dont buy the uhc , i will buy an astronomic uhc in the future)
So far i have loved the views of m42 (i have observed many more objects)and now thats its fading into the suns glare, i m starting to find more and more objects.Hoping to observe the veil and the lagoon nebula as long as some planetaries and definetly globulars(which i ve heard that they dont take filters(am i correct?). I ve heard that the oiii enhances contrast and dims the object, but is the dimming worth the additional contrast from the uhc?
i havent yet observed my first planetary , but i am planning to soon.I m really excited to see one!
I will make another thread similar to this then,asking questions that may arise and reach a conclusion.
I wrote this thread to ask about your preferences with filters(oiii or uhc) and for advice on what i should buy according to the objects i want to view)
thanks, any advice will be useful.
My first attempt at M57. I attempted to capture the extended halo by gathering some OIII and Ha data and then blending these into Blue and Red channels, respectively of an LRGB image. The image below represents about 21 hours and was taken with my Esprit 150.
LIGHTS: L:13, R:13,G:8. B: 10 x 600s; Ha:13, OIII:14 x 1800s. DARKS:30, BIAS:100, FLATS:40 all at -20C.