Ha LRGB processing

By |2018-10-16T11:05:57+00:0016 October 2018|Categories: Technique|

From Cloudy Nights:

Ha/RGB Processing

Start with well-processed H-alpha (as grayscale) and RGB images. Process each separately at first.
Register the two images.
Convert the H-alpha image to RGB.
Delete (make black) the green and blue channels.
Select all, copy, and paste this red image onto the RGB image.
Change the blend mode on this layer to “lighten.”
Adjust the histogram (mainly gamma) of the H-alpha layer to bring its brightness up a bit (gamma ~1.3).
Flatten this image.
Select all, copy, and paste this image onto the original grayscale H-alpha image.
Change the blend mode to “lighten.”
Flatten this image.
Select all, copy, and paste this image onto the RGB+H-alpha image.
Change the blend mode to “luminosity.”
Change the opacity to ~50%.
Season to taste.


Hubble palette colour manipulation

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Observatory build

By |2018-05-28T11:00:36+00:0027 May 2018|Categories: News, Technique|

Old observatory going away, new observatory with Pulsar 2.2m short height dome going up on new wooden walls. The whole thing will sit on top of the remnants of walls from an old WWII air raid shelter. Watch this space…

The old run-off roof one lasted about 10 years without any signs of moving in some very strong winds (the previous 2 had roofs blow off into the field!). It did however leak pretty badly at the corners.


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Plato project

By |2017-09-30T20:46:29+00:0030 June 2017|Categories: Plato project, Technique|

Image Plato crater from Lunar sunrise to sunset and make a timelapse.

From:  79 deg phase, 7.8 days
To:       259 deg phase, 23.5 days, -40.7 deg illumination

Will need daytime imaging so I have a ZWO 850nm IR pass filter for use with the DBK camera if the camera is sensitive enough at these wavewlengths (it is!). Take all images in IR.

Day Actual Day Date Comments
9 9.41 2017-08-01  Too small. Needs re-done and with correct alignment.
10  10.59  2017-09-30
11  11.51  2017-08-03
13  13.54  2017-08-05
15  15.53  2017-08-07
16  16.56  2017-08-08
18  17.59 2017-08-09
20  20.62  2017-08-13  A good sharp image
21  21.57  2017-09-12

ZWO 850 IR transmission characteristics

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EQ6 strip down and belt mod

By |2016-07-12T17:02:52+00:0012 July 2016|Categories: News, Technique|

Taking the summer twilight zone in Scotland as an opportunity to strip down my EQ6 mount which was getting stiff, especially in Dec. Disassembly was quite straightfoward apart from one of the RA bearings which got a little damaged. However, these are known to be poor quality so I’ve also bought 4 new bearings for the RA and Dec worms to replace them. Thanks to Chris Bailey on this UKAI thread for the info.

Also decided to do a belt mod at the same time to try and remove some of the awful errors in the drive train. I chose the Rowan belt mod. Let’s see how it goes.

Got some white lithium grease to replace the seriously gunky stuff that covers everything.

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Remove star trailing

By |2015-10-10T14:26:39+00:0010 October 2015|Categories: Technique|

In Photoshop:

  • Create a duplicate layer
  • Set layer to Darkness
  • “Nudge” layer until stars are circular
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Field of view and CCD data

By |2019-05-01T10:19:20+00:005 July 2015|Categories: Technique|

Orion Optics 250mm f4.8 Newtonian

Atik 460EX

4.54 micron pixels
2750 x 2200 pixels
FOV 0.6 x 0.48 degrees / 36′ x 28.8′

1×1 0.79″/pixel
2×2 1.58″/pixel
3×3 2.37″/pixel
4×4 3.16″/pixel

Canon EOS 600D

5184 x 3456 pixels
4.3 micron pixels
FOV: 1.06 x 0.71 degrees / 63.6′ x 42.6′

Altair Astro/GSO RC8 203/1624mm f/8

Atik 460EX

4.54 micron pixels
2750 x 2200 pixels
FOV 26.41′ x 21.13′

1×1 0.58″/pixel
2×2 1.15″/pixel
3×3 1.73″/pixel
4×4 2.31″/pixel

Canon EOS 600D

5184 x 3456 pixels
4.3 micron pixels
FOV: 47.3′ x 31.53′

Skywatcher 200P 200mm/1000mm f/5

Atik 460EX

4.54 micron pixels
2750 x 2200 pixels
FOV 42.92′ x 34.34′

1×1 0.94″/pixel
2×2 1.87″/pixel
3×3 2.81″/pixel
4×4 3.75″/pixel

Canon EOS 600D

5184 x 3456 pixels
4.3 micron pixels
FOV: 1.28° x 0.85°

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LRGB processing

By |2017-01-31T10:52:42+00:0021 September 2014|Categories: Technique|

atik_460ex_ccd_cameraThis is for my benefit so that I don’t forget how to process LRGB. Added a new Techniques menu item at top just in case it’s any use for anyone else.

Got a new ATIK 460EX and SX Filter wheel with LRGB and Ha.

In Neublosity 3:

  1. Pre-process with Bad Pixel Map and Flats LRGB
  2. Batch Align – Save each file- L R G B
  3. Batch resize R G B to 1.5 (for L 2×2/RGB 3×3)
  4. Batch align – just save files R G B
  5. Image – RGB Colour Synthesis – just resized and aligned R G B
  6. starlight_xpress_motorised_filter_wheelBatch align L and RGB – just save files
  7. Convert the 2 files to TIFF

In Photoshop CC:

  1. Open RGB file
  2. Enhance levels and curves
  3. Add L as layer on top of RGB
  4. Process L layer levels and curves
  5. Set blend mode to Luminosity
  6. Flatten and final process.
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