Thanks Che, Benedikt and Mario.
Animaal, if this were my second DSO ever, i'd be well stoked!
Sure, there's things to improve on (tracking is one of them), but, man, you got a galaxy here!
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- m51_20140604_235900.jpg (36.42 KiB) Viewed 10006 times
Benedikt is right when he says that LP filters do some harm - mostly with regards to your colour balance (you're then missing a part of the spectrum and no amount of color balancing is going to get it back). That said, I know Mario here images quite successfully with LP filters. Then, there is also the technique of gather luminance signal with a LP filter, and gathering some color information without the LP filter. Combining them at the end should yield (almost) 'correct' coloring.
Regardless, you should be able to still gather decent data on the brighter objects under LP, as you did here.
This is how I processed our image. I guess the biggest difference with Benedikt's version is that I (as he also mentioned) used the Color module at towards the end of the processing.
--- Auto Develop
To see what we got. I can see a blue bias, stacking artifacts, signs of heavy noise, oversampling and tracking issues.
--- Bin
Parameter [Scale] set to [(scale/noise reduction 50.00%)/(400.00%)/(+2.00 bits)]
To make use of the oversampling/poor tracking. As Benedikt already indicated, we could/should probably bin more.
--- Crop
To frame the galaxy a bit better.
Parameter [X1] set to [477 pixels]
Parameter [Y1] set to [742 pixels]
Parameter [X2] set to [1416 pixels (-575)]
Parameter [Y2] set to [1302 pixels (-46)]
--- Wipe
To get rid of the blue bias and gradients.
I used the vignetting preset.
Parameter [Temporary AutoDev] set to [Yes] so we can better see what the freed up dynamic range lets us do later on.
Parameter [Dark Anomaly Filter] set to [7 pixels] to make sure the noisiness doesn't create 'false' background calibration points for Wipe to latch on to.
--- Auto Develop
The 'real'/final global stretch (you can also use a manual Develop for this).
I created an ROI (click & drag) over M51A and M51B.
Parameter [Ignore Fine Detail <] set to [5.2 pixels] to make AutoDev ignore noise (otherwise it will optimise the stretch to also show the fine noise).
Parameter [Outside ROI Influence] set to [5 %] to make AutoDev ignore anything outside the ROI more.
--- HDR
Reveal preset.
--- Wavelet Sharpen
To taste.
Parameter [Amount] set to [300 %]
Parameter [Small Detail Bias] set to [95 %]
--- Life
Good call by Benedikt to use the Life Isolate preset. It really helps pushing the noise back.
--- Color
Had to reduce the green a little. A good color balance shows the full range of star temperatures, blue/purple outer rims in the galaxy and a yellow core.
Parameter [Blue Bias Reduce] set to [1.49]
Parameter [Green Bias Reduce] set to [1.23]
Parameter [Red Bias Reduce] set to [1.06]
I set Parameter [Cap Green] to [To Yellow] to kill any remaing green color noise.
--- Wavelet De-Noise
Took a bit of tweaking, but the result was much helped by the Isolate preset in the Life module. I settled for the following;
Parameter [Scale 5] set to [90 %]
Parameter [Scale Correlation] set to [4]
Parameter [Color Detail Loss] set to [7 %]
Parameter [Grain Size] set to [11.2 pixels]
Parameter [Read Noise Compensation] set to [8.42 %]
Parameter [Smoothness] set to [71 %]
Hope this helps!
