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Summer Fireworks!

ollypenrice

By ollypenrice
in Imaging - Deep Sky

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ollypenrice

ollypenrice

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I'm really enjoying this one! The challenge is to make the most of the FL available and get a good controlled starfield in the bright Milky Way. Ha should really make it sing, I hope. This is LRGB so far.

Kit; combined operations for colour. Altair Astro 115 triplet on iOptron iEQ45 with Atik 4000 OSC, 3 hours. Plus TEC140 on EM200 in RGB, total 3 hours. And Lum, TEC140, 3 hours.

Ha to follow. It looks a bit clipped on Smugmug despite a shift in the gamma point to suit, but it isn't really.

Felt like going a bit mad on the colour but then toned it down a bit.

Olly

NGC6946, The Fireworks, or Firecracker, galaxy.

NGC4969-LRGB-X2.jpg

NGC4969CROP2-X2.jpg

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Grinde

Grinde

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Oooh that's really nice! Great job on the galaxy, & awesome starcolors

Since I can only fit 5 filters in my filterwheel & really really like my 3 NB filters (& really really dislike opening the camera to replace the filters), I've been starting to think about collecting color using an osc... Would one notice the differance between a LRGB image vs a L+osc image, taken with the same scope?

Since I give my rgb-layer a slight blur before merging it with the lum, I guess I wouldn't notice the small resolution-loss of the color 'cause of the bayer matrix? I'm just guessing here, hoping you have some hands-on experiance of the matter?

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RobH

RobH

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Graet stuff Olly, and very nicely processed....I remember when I imaged this last year that it was tricky to stretch the galaxy while still controlling the starfield.

Ha does add a bit of sparkle...well worth grabbing some.

I love the widefield view.

I'm currently agonising about buying an MX25C to do widefiled colour....you may have convinced me!!

Cheers

Rob

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ollypenrice

ollypenrice

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Oooh that's really nice! Great job on the galaxy, & awesome starcolors

Since I can only fit 5 filters in my filterwheel & really really like my 3 NB filters (& really really dislike opening the camera to replace the filters), I've been starting to think about collecting color using an osc... Would one notice the differance between a LRGB image vs a L+osc image, taken with the same scope?

Since I give my rgb-layer a slight blur before merging it with the lum, I guess I wouldn't notice the small resolution-loss of the color 'cause of the bayer matrix? I'm just guessing here, hoping you have some hands-on experiance of the matter?

Yes, I use both versions of the Atik 4000 all the time and bought the OSC one after receiving it for doing a colour v mono article in Astronomy Now. I already had the mono.

NB and OSC work well together. I use that formula regularly, mostly in camera lens images where changing filters is not practicable. Also, if you have a high end apo for the colour something much cheaper will be almost as good in NB so you can even make a side by side rig. For this winter I will set this up with FSQ85 for colour and ZS66 in NB, both with FLs around 330mm.

The OSC is slower, likes longer subs and is best dithered. It is sometimes hardly any different from the mono but then, for reasons I never understand, it is disappointing on some objects, most notably galaxies. It might just be me though! Loss of resolution is very slight and greatly exaggerated in most discussions. You can still extract a synthetic L layer and process that for sharpness.

Olly

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ollypenrice

ollypenrice

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Graet stuff Olly, and very nicely processed....I remember when I imaged this last year that it was tricky to stretch the galaxy while still controlling the starfield.

Ha does add a bit of sparkle...well worth grabbing some.

I love the widefield view.

I'm currently agonising about buying an MX25C to do widefiled colour....you may have convinced me!!

Cheers

Rob

Thanks Rob. Guess which image was open on one of my screens while working on this one?? Inspirational. Can't wait for the Ha.

I used the 'RGB only' as the starfield and layered in just the galaxy from the LRGB, much harder stretched from just above the background value. The L layer was a blend of 3 hours L and a synthetic L derived from the 6 hours RGB.

I'm sure I got the idea of using RGB only for the stars from you, no?

Olly

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Coco

Coco

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Nicely done Olly, a veritable spread of coloured stars , very detailed considering the target size is less than 1/4 of M33 or less than 1/2 of M101

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MartinB

MartinB

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Lovely rich colour both in the stars and the galaxy. The widefield does it for me, it's a beauty. Is the other a crop?

Just trying to work out what you did here. Is the starfield from the 115mm OSC data and the galaxy from the TEC L [RGB] RGB. You didn't use the 115 OSC to add into the mix for the galaxy. Is that right? The 3 hours RGB - is that total or 3 hours per channel?

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ollypenrice

ollypenrice

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Lovely rich colour both in the stars and the galaxy. The widefield does it for me, it's a beauty. Is the other a crop?

Just trying to work out what you did here. Is the starfield from the 115mm OSC data and the galaxy from the TEC L [RGB] RGB. You didn't use the 115 OSC to add into the mix for the galaxy. Is that right? The 3 hours RGB - is that total or 3 hours per channel?

Sorry Martin, I think I gave a garbled account!

I took 3 hours OSC in the 115 and an hour per channel RGB in the TEC140/mono.

I combined these about 50/50.

This is the starfield you see. I did spend quite a while on it.

Then I took 3 hours lum and extracted the lightness layer from the OSC/RGB in Lab mode and combined the two into a new Lum (lightness) layer.

I replaced the old lightness layer with the new one into an LRGB image.

Then I pasted this LRGB onto the OSC/RGB and erased the stars but not the LRGB galaxy.

There will be a written test on all this later!!!

The close up is a crop but adjusted because SmugMug messes with the black point and saturation. The adjustment is not so good as it turns out. A straight crop of the widefield would, in the end, have been slightly nicer and will follow... However, I thought the resolution pretty good for the aperture and FL. Two good refractors.

Olly

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MartinB

MartinB

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Thanks for the explanation Olly. Have you tried just using your 3 hours of luminence rather than combining with the L channel from the colour data for comparison? I'd be concerned about degrading my 3 hours of pristine luminence. The only time this technique has worked form me is when I've had the same amount of exposure in each colour channel as the luminence. I've never done anything quite as complicated as you've just done though!

It would be interesting to see the OSC/RGB/L compared with the L

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ollypenrice

ollypenrice

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Thanks for the explanation Olly. Have you tried just using your 3 hours of luminence rather than combining with the L channel from the colour data for comparison? I'd be concerned about degrading my 3 hours of pristine luminence. The only time this technique has worked form me is when I've had the same amount of exposure in each colour channel as the luminence. I've never done anything quite as complicated as you've just done though!

It would be interesting to see the OSC/RGB/L compared with the L

This was a new one for me too, Martin, and I did compare the Lightness+luminance with the pure luminance. I felt the blend was a tad better, particularly in the faint stuff so far as noise was concerned. If I'd had 6 hours of pure luminance I might have gone with it but for a small galaxy in a lot of sky we decided to give it a whizz and move on to the Ha since even here the nights are quite short. I reckon there is not much left in it as far as resolution goes but that may be complacency on my part. It will depend on the target but I don't know how much small scale information is really available in this one.

Olly

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ollypenrice

ollypenrice

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A subject dear to my heart as well, as it is the way I am leaning with mono and OSC combined.

Watching with interest, and hoping to sponge as much info as I c an.

Gary

Gary, look out for Harel Boren on this subject. He's very talented and is also experimenting with combined cameras.

Olly

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gbealnz

gbealnz

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Will do Olly, I have seen his posts on CN's, he uses an 8" newt IIRC. I have a pair of images of M22, one mono and one OSC, and can't for the life of me combine/merge them with Images Plus which I use. It will not be the software's fault, it will be all mine. Just need to learn how.

Gary

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ollypenrice

ollypenrice

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Will do Olly, I have seen his posts on CN's, he uses an 8" newt IIRC. I have a pair of images of M22, one mono and one OSC, and can't for the life of me combine/merge them with Images Plus which I use. It will not be the software's fault, it will be all mine. Just need to learn how.

Gary

Registar is the software of choice. I coudn't live without it.

Olly

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