M31

[Cheman]

Ivo
StarTools just continues to amaze me.
I hadn't imaged M31 in quite a while.
I took 50 10min subs(osc camera
new bias and new flats
stacked in DSS
and about 5 minutes in StarTools and this is the result
http://astrob.in/123053/0/ Tomorrow on my work computer I'll give it another try on a better monitor and try to tweak some things, but hard to imagine much improvement, but then again Startools continues to amaze me so you never know
Thanks again for GREAT and fun software
Che

Edit: 2nd version up

[Cheman]

OK, so I think I was wrong. In my opinion, a lot of improvement. Twenty minutes instead of 5
final version http://astrob.in/123053/C/

[Alvinillo]

Really beautiful image!

As you are an experienced 'image processor' I'll be a little picky Stars that are inside the galaxy core have some ringing artifacts and look like blotches. I suppose it is because of star mask protection at some stage. May be some sintethized stars could help to fine tune them.

Don't be wrong, I like the image a lot, especially the color balance. Good work

[Cheman]

Hi Alvinillo
Thanks for the comments. Reading your suggestions is a help to improve my processing. Lots of times I get too involved in one aspect or another of an image, possibly at the expense of another aspect. When zooming in, I see the issues with some of the stars. I think some of that may have been introduced in the Decon module, but not sure.
I also, on this image, did not see much difference after turning off tracking and applying noise reduction. I tried a few different grain size settings without seeing a lot of difference. Maybe there just wasn't much noise in the first place?
As an overall image, viewed as a whole, I am very pleased with it overall.
Thanks for the comment on the color balance. I still struggle with that in Startools, and find I always have to play with that a lot. Dont know if its because of my data, my processing, or my expectations. But this time, to my eye, I nailed the color, maybe not from a scientific view, but from a pretty picture angle.
Below is my workflow for this image, any suggestions always welcome.
Che
StarTools 1.3.5.289

Fri Sep 26 12:51:59 2014

-----------------------------------------------------------

File loaded [C:\Users\dochaton\Desktop\M31crop71\M31crop71.tiff].
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [UNKNOWN] set to [Yes]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [4 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [75 %]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [93.94 %]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [Off]
--- Deconvolution
Parameter [Image Type] set to [Deep Space]
Parameter [Mask Behavior] set to [De-ring Mask Gaps, Hide Result]
Parameter [Radius] set to [1.5 pixels]
Parameter [Iterations] set to [6]
Parameter [Regularization] set to [1.00 (optimal noise and detail)]
Parameter [Mask Fuzz] set to [8.0 pixels]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [94.28 %]
Parameter [Blue Luminance Contrib.] set to [101 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [Off]
--- Contrast
Parameter [Expose Dark Areas] set to [Yes]
Parameter [Compensate Gamma] set to [Yes]
Parameter [Precision] set to [512 x 512 pixels]
Parameter [Dark Anomaly Filter] set to [4 pixels]
Parameter [Aggressiveness] set to [82 %]
Parameter [Dark Anomaly Headroom] set to [15 %]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [94.95 %]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [Off]
--- Wavelet Sharpen
Parameter [Intelligent Enhance] set to [Yes]
Parameter [Scale 1] set to [100 %]
Parameter [Scale 2] set to [100 %]
Parameter [Scale 3] set to [100 %]
Parameter [Scale 4] set to [100 %]
Parameter [Scale 5] set to [100 %]
Parameter [Mask Fuzz] set to [8.0 pixels]
Parameter [Amount] set to [100 %]
Parameter [Small Detail Bias] set to [75 %]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [94.63 %]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [Off]
--- HDR
Parameter [Small Detail Precision] set to [Max]
Parameter [Channels] set to [Brightness & Color]
Parameter [Algorithm] set to [Reveal DSO Core]
Parameter [Dark/Bright Response] set to [0.93]
Parameter [Detail Size Range] set to [110 pixels]
Parameter [Noise Suppression] set to [Off]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [94.81 %]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [Off]
--- Life
Parameter [Detail Preservation] set to [Linear Brightness Mask]
Parameter [Compositing Algorithm] set to [Multiply, 2x Gamma Correct]
Parameter [Inherit Brightness, Color] set to [Off]
Parameter [Output Glow Only] set to [No]
Parameter [Airy Disk Sampling] set to [128 x 128 pixels]
Parameter [Airy Disk Radius] set to [8 pixels]
Parameter [Glow Threshold] set to [4 %]
Parameter [Detail Preservation Radius] set to [20.0 pixels]
Parameter [Saturation] set to [50 %]
Parameter [Strength] set to [27 %]
Parameter [Mask Fuzz] set to [1.0 pixels]
--- Color
Parameter [Cap Green] set to [To Yellow]
Parameter [Bias Slider Mode] set to [Sliders Reduce Color Bias]
Parameter [Style] set to [Scientific (Color Constancy)]
Parameter [LRGB Method Emulation] set to [50/50 Layering]
Parameter [Dark Saturation] set to [5.00]
Parameter [Bright Saturation] set to [3.00]
Parameter [Saturation Amount] set to [165 %]
Parameter [Blue Bias Reduce] set to [1.46]
Parameter [Green Bias Reduce] set to [1.97]
Parameter [Red Bias Reduce] set to [1.97]
Parameter [Mask Fuzz] set to [1.0 pixels]
--- Wavelet De-Noise
Parameter [Scale 1] set to [90 %]
Parameter [Scale 2] set to [90 %]
Parameter [Scale 3] set to [90 %]
Parameter [Scale 4] set to [90 %]
Parameter [Scale 5] set to [0 %]
Parameter [Mask Fuzz] set to [1.0 pixels]
Parameter [Scale Correlation] set to [3]
Parameter [Color Detail Loss] set to [12 %]
Parameter [Brightness Detail Loss] set to [12 %]
Parameter [Grain Size] set to [2.2 pixels]
Parameter [Read Noise Compensation] set to [Off]
Parameter [Smoothness] set to [75 %]
--- Repair
Parameter [Radial Samples] set to [32]
Parameter [Sub Sampling] set to [4x]
Parameter [Algorithm] set to [Redistribute, Core Is Brightest Pixel]
Parameter [Grow Mask] set to [0 pixels]
--- Magic
Parameter [Mode] set to [Tighten]
Parameter [Mask Grow] set to [1 pixels]
Parameter [Iterations] set to [1 pixels]
File saved [C:\Users\dochaton\Desktop\M31crop71\M31final.tiff].
File saved [C:\Users\dochaton\Desktop\M31crop71\M31final.jpg].

[Cheman]

At the suggestion of Alvinillo,I tried reworking my image to try to improve the stars. I also increased the color a bit, and tweaked a few other things. I tried to use the synth module on the stars, but didnt like my result, probably due to being unfamiliar with its settings. So I tried processing the stars separately from the galaxy.
First time I did that. I think the image is improved. http://astrob.in/123053/D/ What do you think?
Question for Ivo, who I hope is on a much deserved hiatus.
When I removed the stars, halos remained. I tried many different settings. What is the best method to get rid of these. I found I could get rid of a lot in the Life module, isolate mode, but when the settings removed enough of them, it affected the galaxy a bit.

thanks
Che

[Rowland]

It is a very nice image. The detail and contrast is superb.

[Cheman]

thanks very much Rowland

Che

[Alvinillo]

I've seen the second version and you have got rid of ringing but image has lost detail. I don't know if this is the best way, but taking your original image as source, I've tried to repair some ringing stars with the Repair module. I think it works but it is a pain to build a good mask

Star Repaired

Star_Repair.jpg (345.34 KiB) Viewed 12089 times

Regards

[Cheman]

Thanks for looking at this Alvinillo. On my latest processing, I did not use the deconvolution, so this leads me to beleive that the ringing was introduced there, either in the mask or the decon settings. This might also explain a slight loss of detail.
Che

[admin]

Hi guys,

The artifacts are most likely the result of the Repair module. This can happen when not enough of the star has been selected in the mask, or when the stars are very much bent out of shape. There is a nice fix for this that works well most of the time; After you've repaired your stars, launch the Layer module, then pop over to the mask editor and grow your mask once or twice such that the artifacts/rings are encompassed by the mask. Set Blend mode to 'Lighten' and bump up the Kernel size (we'll use the default Gaussian blur) and blend it in nicely with some Mask Fuzz.

The image, though, is gorgeous! Love the coloring too.