M31

[ChrisLX200]

What I usually do here with LRGB-type images is use the star mask and process the colour of stars and and colour of other features separately. Load your saved star mask (you do save it, yes?) then go into the colour tool and click 'Sample'. Based on the assumption that the average star colour is white (it may not be, but you are free to adjust - it may be necessary if there's a lot of interstellar dust turning the stars more brown-ish, or you can ignore a couple of very bright coloured stars - in which case remove them from the mask). The colour bias offsets will be set in the panel to the right when you click 'Sample'. Go back into Mask and invert it, then back to the colour tool. The settings from 'sample' are sticky so will stay the same. Now you have a white balance set so you can adjust the saturation (not for the stars at this time - just for all other features outside the mask). When happy with that then go back to the mask and invert again and then back into the colour tool. Now you can adjust the saturation of the stars. At each of the two stages you can tweak the colour bias a little if you don't like the result, but it should be pretty close.

ChrisH

[ChrisLX200]

http://www.astrobin.com/272310/?nc=user

three nights, 6+ hours of total integration time, hooray for M31!!

For those who are Startools expert here, I'm asking a favour

https://www.dropbox.com/s/d21v0oyngp4d1 ... 1.fts?dl=0

could someone try to process the image with our beloved tool? I'd like to have a sort of test to understand how much I'm loosing of the image potential because of my poor experience

Here's my log, you might find it strange but this is the reason: my buddy knows NOTHING about image processing but as the right "eye" to identify what it is beautiful and what it is not, so I let him try any combination of startools modules (infinite monkey theorem ) and then I collect his logs and his result (which has always something that improves my attempts) and try to produce something with the right color balance and noise reduction

Your dropbox file is an image of M51 Whirlpool galaxy (sort of!). A nightmare mixture of defects Still, just for fun, I processed the middle bit and ended up with something that looked a little like M51 surrounded by flying donuts

[micheleorsini]

Hi Startools friends,
sorry for the late reply and thank you for the tips and suggestions.
I'm currently aware of three defects of my gear/procedure and I'm working on them: flat generation (white panel is too small), focus (can never get to optimal) and collimation (not easy in a 200mm with short focal ratio - f4 - even with 4mm eyepiece, maybe I need a barlow lens). I think that the problems in wiping comes from my poor flats.

ChrisH where did you find that image? It is not mine, I swear!! I clicked on the link on my post to verify: downloaded fts file again and an M31 image appeared.

Following the advice of Richard I came to this image: http://www.astrobin.com/272310/C/?nc=user

Same version with "scientific" colors is here

20161030_M31_r5_scientific_3.jpg (476.74 KiB) Viewed 6429 times

Michele

[Rowland]

Couldn't resist the opportunity.

EDIT: the intent was to extract as much light and color information as possible. The classical black background is nice but an object the size of M31 is likely to brighten up its surroundings. A bit pressed for time I didn't pay a lot of attention to detail or star color as per Chris's mask technique. There appears to be a lot of Ha and blue star regions.

20161030_M31.jpg (364.9 KiB) Viewed 6421 times

Code: Select all

StarTools 1.4.324
Sat Dec 17 18:15:47 2016
-----------------------------------------------------------
File loaded [/home/geoland/Astrophotography/20161030_M31.fts].
--- 
--- Bin
Parameter [Scale] set to [(scale/noise reduction 35.38%)/(798.89%)/(+3.00 bits)]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [85.31 %]
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 [4.0 pixels]
--- Crop
Parameter [X1] set to [28 pixels]
Parameter [Y1] set to [30 pixels]
Parameter [X2] set to [1798 pixels (-44)]
Parameter [Y2] set to [1080 pixels (-149)]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [91.95 %]
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 [1.9 pixels]
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [UNKNOWN] set to [No]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [1 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 [96.98 %]
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 [4.0 pixels]
--- HDR
Parameter [Small Detail Precision] set to [Max]
Parameter [Channels] set to [Brightness Only]
Parameter [Algorithm] set to [Reveal DSO Core]
Parameter [Dark/Bright Response] set to [Full]
Parameter [Detail Size Range] set to [512 pixels]
Parameter [Noise Suppression] set to [1.2]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [Off]
Parameter [Outside ROI Influence] set to [15 %]
--- 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 [1 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [80 %]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [Off]
Parameter [Outside ROI Influence] set to [15 %]
--- HDR
Parameter [Small Detail Precision] set to [Max]
Parameter [Channels] set to [Brightness Only]
Parameter [Algorithm] set to [Reveal DSO Core]
Parameter [Dark/Bright Response] set to [Full]
Parameter [Detail Size Range] set to [512 pixels]
Parameter [Noise Suppression] set to [1.2]
--- 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 [Straight CIELab Luminance Retention]
Parameter [Dark Saturation] set to [2.00]
Parameter [Bright Saturation] set to [Full]
Parameter [Saturation Amount] set to [200 %]
Parameter [Blue Bias Reduce] set to [1.03]
Parameter [Green Bias Reduce] set to [1.05]
Parameter [Red Bias Reduce] set to [1.35]
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 [6]
Parameter [Color Detail Loss] set to [12 %]
Parameter [Brightness Detail Loss] set to [12 %]
Parameter [Grain Size] set to [7.0 pixels]
Parameter [Read Noise Compensation] set to [Off]
Parameter [Smoothness] set to [75 %]
Undo.
Redo.
Undo.
Redo.
Undo.
--- 
Parameter [Quality] set to [Medium]
Parameter [New Darker Than Old] set to [Yes]
Parameter [Grow Mask] set to [0 pixels]
Parameter [Neighbourhood Samples] set to [0]
Parameter [New Must Be Darker Than] set to [Off]
Parameter [Neighbourhood Area] set to [200 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 [6]
Parameter [Color Detail Loss] set to [20 %]
Parameter [Brightness Detail Loss] set to [20 %]
Parameter [Grain Size] set to [4.5 pixels]
Parameter [Read Noise Compensation] set to [Off]
Parameter [Smoothness] set to [75 %]
Undo.
Redo.
Undo.
--- Wavelet De-Noise
Parameter [Scale 1] set to [95 %]
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 [6]
Parameter [Color Detail Loss] set to [20 %]
Parameter [Brightness Detail Loss] set to [20 %]
Parameter [Grain Size] set to [4.5 pixels]
Parameter [Read Noise Compensation] set to [Off]
Parameter [Smoothness] set to [75 %]
--- 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 [1.0 pixels]
Parameter [Amount] set to [50 %]
Parameter [Small Detail Bias] set to [75 %]
File saved [/home/geoland/Astrophotography/20161030_M31.tif].

[micheleorsini]

Interesting "perspective" of M31, Rowland, thank you!