Colour of NGC 2903

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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almcl
Posts: 156
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Colour of NGC 2903

Post by almcl »

Following on from the wipe thread viewtopic.php?f=10&t=1769, I did manage to get an image or two out of the various stacks. This one uses a synthetic Lum from 50 x 3 minute subs shot with a CLS filter combined with RGB from 60 x 1 minute subs shot with no filter.

Really pleased at the amount of detail that is visible in the core but a bit concerned at the complete lack of any blue, apart from what I think may be random 'noise' pixels scattered around and in the core, in the final result. The blue channel looks distinctly weaker in FITS liberator (the only software I have for examining separate channels in a FITS file) and I wonder if this is a fault in the stacking process (DSS 4.2.4 Beta 3, averaging) or, more likely, operator error?

And, for the moment, am ignoring the background mottle and the weird artefacts below and to the right of centre!
NewComposite NGC2903.jpg
NewComposite NGC2903.jpg (129.86 KiB) Viewed 647 times
Skywatcher 190MN, astro modded Canon 700d, cls ccd, or Ha or Oiii filters, guided by OAG, ASI120, PHD2
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Re: Colour of NGC 2903

Post by admin »

Strange about the very yellow coloring. How did you process this? (log?)

It's usually not very useful to compare individual channels if they have not been calibrated and white-balanced yet.

By the way, you can examine a single channel in StarTools easily by using the Compose module; just load the color stack into the one channel you're after and it will extract the correct channel and turn it into a mono image.
Ivo Jager
StarTools creator and astronomy enthusiast
almcl
Posts: 156
Joined: Wed Jan 21, 2015 7:15 pm
Location: Shropshire. UK

Re: Colour of NGC 2903

Post by almcl »

Here's the log (with mask data removed - full version with masks is in the dropbox folder):
-----------------------------------------------------------
StarTools 1.6.391beta
Wed Mar 25 22:43:25 2020
-----------------------------------------------------------
Loading luminance channel data
File loaded in LRGB module [E:\Astronomy\2020\2020-03-24 NGC 2903\Autosave001.fts].
Loading red channel data
File loaded in LRGB module [E:\Astronomy\2020\2020-03-25 NGC 2903\Autosave.fts].
Loading green channel data
File loaded in LRGB module [E:\Astronomy\2020\2020-03-25 NGC 2903\Autosave.fts].
Loading blue channel data
File loaded in LRGB module [E:\Astronomy\2020\2020-03-25 NGC 2903\Autosave.fts].
--- Compose
Parameter [Luminance, Color] set to [L + Synthetic L From RGB, RGB]
Parameter [Color Ch. Interpolation] set to [On]
Parameter [Lum Total Exposure] set to [2h05m (125m) (7500s)]
Parameter [Blue Total Exposure] set to [1h00m (60m) (3600s)]
Parameter [Green Total Exposure] set to [2h00m (120m) (7200s)]
Parameter [Red Total Exposure] set to [1h00m (60m) (3600s)]
Image size is 5208 x 3476
Type of Data: Linear, was not Bayered, or was Bayered + white balanced
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [Off]
Parameter [Outside RoI Influence] set to [15 %]
Parameter [RoI X1] set to [0 pixels]
Parameter [RoI Y1] set to [0 pixels]
Parameter [RoI X2] set to [5208 pixels (-0)]
Parameter [RoI Y2] set to [3476 pixels (-0)]
Parameter [Detector Gamma] set to [1.00]
Parameter [Shadow Linearity] set to [50 %]
--- Rotate
Parameter [Angle] set to [2.20]
--- Crop
Parameter [X1] set to [695 pixels]
Parameter [Y1] set to [663 pixels]
Parameter [X2] set to [4351 pixels (-986)]
Parameter [Y2] set to [3337 pixels (-336)]
Image size is 3656 x 2674
--- Bin
Parameter [Scale] set to [(scale/noise reduction 70.71%)/(200.00%)/(+1.00 bits)]
Image size is 2585 x 1890
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [5 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [75 %]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [4.1 pixels]
Parameter [Outside RoI Influence] set to [15 %]
Parameter [RoI X1] set to [1151 pixels]
Parameter [RoI Y1] set to [648 pixels]
Parameter [RoI X2] set to [1362 pixels (-1223)]
Parameter [RoI Y2] set to [1085 pixels (-805)]
Parameter [Detector Gamma] set to [1.00]
Parameter [Shadow Linearity] set to [50 %]
--- Contrast
Parameter [Expose Dark Areas] set to [No]
Parameter [Compensate Gamma] set to [No]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [5 pixels]
Parameter [Aggressiveness] set to [50 %]
Parameter [Dark Anomaly Headroom] set to [15 %]
Mask used (BASE64 PNG encoded)



--- Life
Parameter [Detail Preservation] set to [Linear Brightness Mask]
Parameter [Compositing Algorithm] set to [Multiply, Gamma Correct]
Parameter [Inherit Brightness, Color] set to [Brightness]
Parameter [Output Glow Only] set to [No]
Parameter [Airy Disk Sampling] set to [128 x 128 pixels]
Parameter [Airy Disk Radius] set to [64 pixels]
Parameter [Glow Threshold] set to [0 %]
Parameter [Detail Preservation Radius] set to [20.0 pixels]
Parameter [Saturation] set to [100 %]
Parameter [Strength] set to [77 %]
Parameter [Mask Fuzz] set to [40.0 pixels]
Mask used (BASE64 PNG encoded)



--- 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 [1000 pixels]
Parameter [Strength] set to [1.2]
--- Wavelet Sharpen
Parameter [Structure Size] set to [Medium]
--- SNR-aware Wavelet Sharpening
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 [4 pixels]
Parameter [Amount] set to [237 %]
Parameter [High SNR Size Bias] set to [85 %]
Parameter [Low SNR Size Bias] set to [0 %]
Parameter [Dark/Light Enhance] set to [50% / 50%]
Mask used (BASE64 PNG encoded)

--- Deconvolution
Parameter [Image Type] set to [Deep Space]
Parameter [Secondary PSF] set to [Off (Primary Only)]
Parameter [Primary PSF] set to [Gaussian (Fast)]
Parameter [Tracking Propagation] set to [Post-decon (Fast)]
Parameter [Primary Radius] set to [1.7 pixels]
Parameter [Iterations] set to [6]
Parameter [Regularization] set to [1.00 (optimal noise and detail)]
Parameter [Mask Fuzz] set to [4.0 pixels]
Parameter [Enhanced Deringing] set to [50 %]
Parameter [Bright Response] set to [Full]
Mask used (BASE64 PNG encoded)


--- Life
Parameter [Detail Preservation] set to [Linear Brightness Mask]
Parameter [Compositing Algorithm] set to [Multiply, Gamma Correct]
Parameter [Inherit Brightness, Color] set to [Brightness]
Parameter [Output Glow Only] set to [No]
Parameter [Airy Disk Sampling] set to [128 x 128 pixels]
Parameter [Airy Disk Radius] set to [4 pixels]
Parameter [Glow Threshold] set to [0 %]
Parameter [Detail Preservation Radius] set to [20.0 pixels]
Parameter [Saturation] set to [100 %]
Parameter [Strength] set to [74 %]
Parameter [Mask Fuzz] set to [1.0 pixels]
--- Color
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 [Matrix] set to [Identity (OFF)]
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 [1.11]
Parameter [Green Bias Reduce] set to [1.25]
Parameter [Red Bias Reduce] set to [1.00]
Parameter [Mask Fuzz] set to [1.0 pixels]
Parameter [Cap Green] set to [100 %]
Parameter [Highlight Repair] set to [Off]
--- Wavelet De-Noise
Parameter [Filter Type] set to [Distance Weighted Outlier Rejection]
Parameter [Grain Size] set to [10.3 pixels]
--- Wavelet De-Noise
Parameter [Scale 1] set to [95 %]
Parameter [Scale 2] set to [95 %]
Parameter [Scale 3] set to [95 %]
Parameter [Scale 4] set to [95 %]
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 Dispersion] set to [10.3 pixels]
Parameter [Non-linear Response <] set to [Off]
Parameter [Smoothness] set to [65 %]
File saved [E:\Astronomy\2020\2020-03-25 NGC 2903\NewComposite.tiff].
Skywatcher 190MN, astro modded Canon 700d, cls ccd, or Ha or Oiii filters, guided by OAG, ASI120, PHD2
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