Recently Browsing 0 members
No registered users viewing this page.
I was thinking, does an apo produce better images than an achromatic refractor for narrow band imaging? Chromatic aberration should not be an issue for NB but I read somewhere that for apo's spherical aberration is corrected for two wavelengths vs one for achromats.
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!
Taken 27 July 19. from my ROR Garden Shed.
I did take the stars out using Starnet but prefered the stars in
30 x 300s SII,Ha,OIII - 2.5Hrs
TS65EQ with Atik EFW2 and ZWO AOG, Lodestar X2 guidcam.
Mesu 200 mount
ZWO 183mm pro at -20C 200 Gain.
Processed in Pixinsight.
Thanks for looking.
Hi still learning the ropes with my new Hypercam 183c pro
i took this image of the heart nebula the other evening, and now I realise I want a scope with a shorter focal length haha.
22x 240s stacked and calibrated in PI. Final touch up in PS 2018
SW ED80 DS pro with Altair light wave 0.8 reducer. Heq5 pro, Altair astro hypercam 183c pro. Guided.
We had a patch of clear skies last Sunday night, and even though it was bitterly cold (and there was ice and snow everywhere) I made the executive decision to get outside and have a go nonetheless. I have to setup and teardown each session, but thankfully I was able to move the car a few metres and take advantage of the nice dry (and ice free) ground underneath.
The plan was to grab some OIII data to go with the Ha I captured on the Heart Nebula a couple of weeks back (see link below) but all I could manage was 8 x 1200s before the clouds rolled in for good. In fact, 3 of the 8 subs were affected by clouds, but I decided to use them anyway as I figured it’s only going to get used for tone mapping, and not luminosity, and at such a short exposure time I really need all the SNR I can get. So I’m being a bit of a naughty boy by posting this before getting a decent amount of OIII first.
This is just a quick once-through process and is still missing some things, so it’s very much a work-in-progress at this stage, but I thought I’d post it anyway and I’ll update the thread as I make changes. So far, all I’ve done is process the OIII image (which involved gradient reduction, stretching, removing the stars then stretching some more, then quite a substantial amount of noise reduction). Then I combined it with the Ha image above in my usual manner, i.e creating a synthetic SII using 60% of the Ha image and 40% of the OIII image, and then combining all 3 using Annie’s Hubble Palette action.
So aside from some more work to refine the colour, I still need to work on the contrast, do some NR and also then finally some star reduction.
C&C welcome as always!
SW 80ED with FF/FR (510mm FL)
HEQ5 Pro Mount (belt mod)
11 x 1200s and 3 x 900s of Ha (2” Baader)
8 x 1200s of OIII (2” Baader)
30 Flats, 50 Bias. Dithered every frame.
Captured in SGP. Stacked in APP. Processed in PS.
Thanks for looking.
The Ha image: