Dark Nebula LBN 468

[tooth_dr]

My first attempt at imaging and processing a dark nebula, and probably my first really good run at the Atik 383L+ in some proper darkness.  I imaged last night from 10pm so I had to content with the moon after midnight.  I haven't used darks because I hadn't built a library of darks past 600s.  Currently doing them now, takes a while at only 4 per hour!

18 x 900s L with Atik 383L+

38 x 300s RBG with Canon 40d

ED80 FF0.85x EQ6

It was nice to see some detail come through.  Please feel free to offer advice.  Processing with DSS and  PS.  I hadn't really a clue on how to process this, and it does look a bit harsh.  The DSLR image was quite horrible too ?

[LightBucket]

Very nice, I like the fact you used the 383 for the luminance and a DSLR for the colour, a much quicker way to get a good detailed image....I want to try that myself, rather than using all the individual filters..

[paul mc c]

cracking shot....love dark nebs.

[tooth_dr]

Thanks William. I think it’s a good idea lol

Thanks Paul. I like them too. Hope to do more. 

[Allinthehead]

That's looking very nice, and an ambitious one too with that moon about. You seem to have lost star colour and i wonder is it from applying to much luminance in one go? @ollypenricegave me great advice last year about applying just enough at one go so that the colours were just fading, blur the image and increase the saturation slightly. Apply the luminance again this time giving a little more, keep repeating the whole process of blurring and increasing saturation until you can apply 100% of the luminance without washing out the colour and obviously don't blur the final iteration. 

[tooth_dr]

19 minutes ago, Allinthehead said:

That's looking very nice, and an ambitious one too with that moon about. You seem to have lost star colour and i wonder is it from applying to much luminance in one go? @ollypenricegave me great advice last year about applying just enough at one go so that the colours were just fading, blur the image and increase the saturation slightly. Apply the luminance again this time giving a little more, keep repeating the whole process of blurring and increasing saturation until you can apply 100% of the luminance without washing out the colour and obviously don't blur the final iteration. 

I’m could give that a go but would need more help ? 

In this case I took the processed RGB DSLR image and pasted the processed Atik L later on top. Set it to Luminance blend et voila. Which explains why it looks like it does ?

[ollypenrice]

3 hours ago, LightBucket said:

Very nice, I like the fact you used the 383 for the luminance and a DSLR for the colour, a much quicker way to get a good detailed image....I want to try that myself, rather than using all the individual filters..

Actually this isn't true. The mono camera will collect signal in RGB considerably faster than the DSLR. There is no free lunch in this game because an OSC only collects 'one shot colour' by collecting its individual colours on a fraction of its pixels, so half get green, a quarter red and a quarter blue. What matters is the total amount of signal collected per colour. Being cooled, less noisy, more sensitive and probably using much better filters, the CCD will do this faster despite the filter changes.

2 hours ago, tooth_dr said:

I’m could give that a go but would need more help ? 

In this case I took the processed RGB DSLR image and pasted the processed Atik L later on top. Set it to Luminance blend et voila. Which explains why it looks like it does ?

That's fine with very strong colour data. The partial application of Lum, followed by a small saturation boost to the RGB layer and a small blur of the L layer before flattening, repeated in iterations, will work better for your case. As mentioned above, you don't blur the L on the last application.

Olly

[tooth_dr]

@ollypenrice I’m waiting on a filter wheel! Currently I run the two cameras in tandem so just getting as much of each at the same time as I can.  I’m going to post my colour data to see if it’s any use to begin with. 

Thanks for your help ??

Adam

[wimvb]

In OSC, you collect three colours in one shot (as the name says), but at a cost of resolution and noise. In a cooled mono camera, you need to do three exposures, but each will have better resolution and less noise, so there is definitely a gain. While it seems that you collect data faster with OSC, in fact to get to a certain image quality, is usually faster with (cooled) mono. Mono is also less sensitive to light pollution, imo. This is because the filters allow a small "gap" between red and green, just where the emission lines of sodium and mercury are, two common light sources in street lamps. And of course, mono allows more efficient collection of nb data.

[LightBucket]

I think to be honest we are aware of the differences between a mono camera and a OSC, I was just saying I like the idea of trying it with a mono CCD and a DSLR...I know that on paper a mono CCD and LRGB filters is quicker, but only in the right hands, and do now I prefer to have a go at the above....sorry but I think you are missing the point of my comment..

[tooth_dr]

I did use a LP filter with my DSLR. I just like the concept of using a £40 camera to collect colour with little fuss, it seems wrong ?

[Xiga]

I agree these dark nebulae are a joy to look at, and for a first go i think you've done very well indeed (i wouldn't have a clue how to go about it myself but would be keen to have a go if you posted the data). 

Don't want to weigh in on the mono vs osc debate above, but i'm a big believer in just using what you've got at hand, so i say using the 40D to capture colour at the same time as the Ha is a great idea. If i had a semi-permanent setup i would probably do the same ?

[Rodd]

Well Adam, Since you asked for opinions, I have 2--the first is I think it is a marvelous image.  What's the test?  Well...it looks lie a dark nebula.  Not an easy task.  And 2, I think the image would benefit by a boost of brightness to the nebula--a small boost of brightness.  I think you have some room to spare before histogram (or curves) lifts begin to reveal noise.  Just my opinion.  Nice image

Rodd

[tooth_dr]

45 minutes ago, Rodd said:

Well Adam, Since you asked for opinions, I have 2--the first is I think it is a marvelous image.  What's the test?  Well...it looks lie a dark nebula.  Not an easy task.  And 2, I think the image would benefit by a boost of brightness to the nebula--a small boost of brightness.  I think you have some room to spare before histogram (or curves) lifts begin to reveal noise.  Just my opinion.  Nice image

Rodd

Thanks Rodd. There is some elements of my processing that I’m struggle to get to grips with. The main one seems to gaining a contrast between the nebula and the background. 

[Rodd]

Just now, tooth_dr said:

Thanks Rodd. There is some elements of my processing that I’m struggle to get to grips with. The main one seems to gaining a contrast between the nebula and the background. 

Join the club.  Its amazing how minimal a tweak has to be to result in big changes in the image.  Tiny increments.  The smallest change in settings that results in a modification that can be observed with the eye.  That way, you creep up on the Rubicon instead of storming it full force.

Rodd