M101 : 2013-05-13

[gboulton]

M101 - 2013-05-13 from Red Zone SE of Nashville, TN USA

• Orion ED80T CF
• CG5 Mount, guided by Orion SSAG and 50mm Guidescope
• EOS 1100D, managed by BackyardEOS
• HoTech SCA Field Flatener
• Baader Moon and Skyglow Nd filter
• 45 x 180" (Top 80% of 56) at ISO 400, 2hr 15m integration time
• 10 x Flats, Bias
• Post in StarTools and PS CS2

Unstretched TIF

This one was one of my toughest images yet to get to where I was happy with it. Relatively little gradient to worry with (Thank you Baader!) but more noise than I'd hoped (Note to self : Please remember to enable PHD dithering BEFORE you start your imaging session...not 40-odd images into it. )

This is about the 9th go at it, and I finally got it to something I was reasonably happy with. I actually wound up handling noise with careful manual stretching, the Contrast module and Dark Anomaly Filters rather than using the actual denoise routine. Turns out, this one had probably the FEWEST steps of any of them. Sometimes less is more, I guess.

• ---Bin
  • Parameter [Scale] set to [(scale/noise reduction 50.00%)/(400.00%)/(+2.00 bits)]
  --- Develop
  • Parameter [White Calibration] set to [Use Stars]
    Parameter [Gamma] set to [0.83]
    Parameter [Skyglow] set to [0 %]
    Parameter [Digital Development] set to [98.95 %]
    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 [0 %]
    Parameter [Dark Anomaly Filter] set to [20.0 pixels]
  --- Crop
  • Parameter [X1] set to [344 pixels]
    Parameter [Y1] set to [247 pixels]
    Parameter [X2] set to [1765 pixels (-380)]
    Parameter [Y2] set to [1167 pixels (-261)]
  --- 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 [30 pixels]
    Parameter [Aggressiveness] set to [49 %]
    Parameter [Dark Anomaly Headroom] set to [0 %]
  --- Wavelet Sharpen (This was done on a mask limited to the basic outline of the DSO...really cut down on the noise, and a technique I may try again)
  • Parameter [Channels] set to [Brightness Only]
    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 [40.0 pixels]
    Parameter [Brightness Mask Power] set to [0.00]
    Parameter [Amount] set to [100 %]
    Parameter [Small Detail Bias] set to [75 %]
  --- Color (Done on the whole image)
  • Parameter [Cap Green] set to [To Yellow]
    Parameter [Bottom End Saturation] set to [Full]
    Parameter [Top End Saturation] set to [Full]
    Parameter [Saturation] set to [98 %]
    Parameter [Blue Ratio] set to [1.02]
    Parameter [Green Ratio] set to [1.00]
    Parameter [Red Ratio] set to [1.01]
    Parameter [Mask Fuzz] set to [1.0 pixels]
  --- Color (Done to just a star mask)
  • Parameter [Cap Green] set to [To Yellow]
    Parameter [Bottom End Saturation] set to [Full]
    Parameter [Top End Saturation] set to [Full]
    Parameter [Saturation] set to [678 %]
    Parameter [Blue Ratio] set to [1.00]
    Parameter [Green Ratio] set to [1.00]
    Parameter [Red Ratio] set to [1.02]
    Parameter [Mask Fuzz] set to [1.0 pixels]
  --- Magic (Only on larger stars)
  • Parameter [Mode] set to [Tighten]
    Parameter [Mask Grow] set to [1 pixels]
    Parameter [Iterations] set to [1 pixels]

[admin]

Have you tried the Life module technique where you define the super structure using a mask and use the Isolate preset? (see video)
There are a good few images on the net by other astrophotographers that you can use to create a reference super structure of M101.
You should be able to get something like this without too much hassle (color to taste obviously );