Blog Archives

Flame and Horsehead Nebula

I’ve got approx 6 hours of Ha and RGB data on the Horsehead and Flame Nebula.  I need more, I aim for around 20 hours.  In the meantime, I am enjoying practising processing using books and internet forums.  Processing is hard, no doubt about it, and it is starting to click for me albeit slowly.  I think the key is similar to normal photography.  The best images are made in the camera no amount of processing will make a poor photo amazing.  Anyway, here is the latest HaRGB combination of this target.

Processing Technique in a Nutshell

Linear Processing

Ha Linear:

  1. Dynamic Crop
  2. DBE
  3. Mask and AT Noise Reduction
  4. Invert Mask and Deconvolution using Star Mask and Local Deringing Support.  Generate PSF using Dynamic PSF.

RGB Linear:

  1. Register against Ha Linear
  2. DBE
  3. Mask and AT Noise Reduction
  4. Invert Mask and Deconvolution using Star Mask and Local Deringing Support.  Generate PSF using Dynamic PSF.

Create HaRGB Linear Image

Create a HaR image:

  1. Extract channels of Linear RGB.
  2. Use Pixel Math to create continuum map x 2. (http://pixinsight.com/tutorials/narrowband/theory/en.html)
    1. C1 = B/N
    2. Denoise using AT the C Map
    3. Use Pixel Math so Bnew = N * C1
    4. Repeat but this time C2 = Bnew/N
    5. Denoise C2
    6. Use pixel math so Bfinal = C2*N
    7. End result is HaR.

Create HaRGB:

  1. Use linear fit setting original R as reference and appy to the new HaR.
  2. Use channel combination to combine HaR with G and B from original image.
  3. Result is HaRGB.

 

Non Linear Processing

Stretch the Image:

  1. Use script Masked Stretch to initiall stretch the image.
  2. Use Histogram to final stretch the image.  Adjust channels if needed so peaks are aligned on R, G and B.

Create LSS+SSS Using Masks:

  1. Create Star Masks to generate LSS and SSS
  2. Use Histogram Transformation to stretch LSS and SSS being careful not to clip any pixels.
  3. Combine LSS and SSS using PixelMath LSS+SSS

Further Processing:

  1. Use HDRMultiscaleTransform
  2. Use LocalHistogramEqualization using clone mask and also invert
  3. User CurvesTransformation for Saturation Boost and Contrast Boost with Star Mask
  4. Use ACDNR

Finishing Touches in PS:

  1. High Pass
  2. Merge Ha with RGB again with Luminosity set to 50%
  3. Add frame and text then save for web

The Moon 19th April 2013

I had a go at some Lunar using my IMG 132E camera.  I spent around 4 hours in the cold getting to grips with the software and settings and practising focusing but I think it paid off.  Before now, I hadn’t really spent the time to learn the camera or the software, too focused on DSO imaging.

So here is a 4 panel mosaic from the 19th April 2013.

For each panel, the best 40% frames out of 1,000 frame AVI were used running at approx 18 fps.  The resolution of the AVI was 1280 x 1024, which is large!  I did experiment with 640×480 which ran at approx 60 fps but I need to revisit that.  I understand there are merits for high frame rate, but I think that may be more important for Plantary imaging rather than Lunar.  I’ll give it another go next time the moon is out over the Summer.

Processing was done in Autostakkert! and Registax 6, with a little post processing in Adobe Photoshop for final touches and saving to JPG.

NGC281 – Pacman Nebula

I’m currently working on NGC281, known as the Pacman Nebula because of it’s resemblance to the computer game Pacman, is located in the Constellation Cassiopeia.  The Nebula is ~9.5kly away, a kilo-light year (kly) being 1,000 light years.  For those not good at sums that’s 9,500 light years away which is exactly how long it took the light to get to my scopes.

This was imaged using both scopes on a side by side setup, with the ATIK 314L+ on the 80 ED and the QHY8L on the 100ED, guided with PHD and controlled by Sequence Generator Pro.

Integration

Atik 314L+: 33 x 600s @ -20C – Baader 35nm H-alpha

QHY8L: 49 x 420s @ -25C – Astronomik LPS (Light Pollution)

The Ha was combined as L to the RGB resulting in an LRGB image.

IC1396 in Ha Comparison of 3 against 10

My current project is to get around 10 hours worth of data for target IC 1396 (Elephants Trunk) using 7nm Ha filter on my Atik 314L+.  Currently I am up to a little over 3 hours with 10 x 20 min subs using a Sky-Watcher 80ED DS-Pro on an NEQ6 Mount.

I am using Sequence Generator Pro for capturing which is an awesome piece of software by Main Sequence Software as it allows me to plate solve and centre my scope each night the weather is favourable so I can continue capturing the data I need.  With UK weather at the moment this the ability to centre with ease is essential for multiple night imaging of one target – highly recommended!

So anyway more data is needed to finish it.  In the meantime I did a comparison of my first night data compared to my first and second night combined.  This is a comparison of 3 subs against 10 subs (subs @ 20 mins).  You can really see the noise reduction in the 10 sub image and some of the finer detail being resolved.

I’ll post the final image once it’s completed.  I may even image some RGB using a OSC and combine to create a HaRGB composite.

Milky Way from near Saint-Jean-d’Angle

Just spent a nice two weeks in France, first to Normandy for 3 days to attempt to visit some museums (hard with a 2yr old) then to a child friendly Gite near Saint-Jean-d’ Angle which is reasonably close to La Rochelle.

You could make out the Milky Way with the eye, although it did look like a cloud.  This shot is taken with a modified Canon 40D on a standard tripod.  Around 60 x 30 second exposures were used and stacked and processed in PixInsight.  I used continuous shooting with a remote shutter locked with the button engaged since my camera is missing its USB port.  Lens was set to 10mm which equates to 16mm on a 1.6x CCD.

 

Aurora Borealis from Marsden, South Tyneside

It’s amazing what you can photograph with a compact digital camera.  I recently acquired a Canon A3350 from the eBay Canon outlet, it’s refurbished and was a decent price so no real complaints.  It’s the only camera I have working at the moment that a human can use (i.e. non Astro) so it was the only choice when a chance to see the Aurora came up on the 17th July 2012.

Due to recent solar activity the Kp index (global geomagnetic storm index with a scale of 0 to 9)  was very high, possibly a 9 I don’t recall, giving an indication that the Aurora Borealis (or Northern Lights) could be seen from lower latitudes than normal.  So, since it was actually clear I decided to pop out to see if anything could be seen.  After around an hour sitting in the car looking North I caught glimpse of something in a NE direction out to sea (I was sitting in a car park in Marsden) and couldn’t believe my eyes.  A stream of stuff was making its way down from the sky by witchcraft to the horizon, like a beam of dim white light.  Hurriedly I got the camera out and tried to take a long exposure to see if it brought out any colours.  Well, it’s now proven trying to keep a camera stable enough by hand resting on the car door was a challenge so I jumped out of the car and used a bin kindly donated by South Tyneside.  I had actually taken my tripod out, but in the rush forgot the shoe that was still attached to the binoculars in the house.

I took a few snaps fighting with a nearly dead battery, sitting on it to warm it up to get a few more shots out.  The shots were OK and serve as proof something was there and I saw it, but they are too grainy and out of focus for anything else.  I think I was more amazed that I had actually seen the Aurora with my own eyes rather than photographed it – something I thought would never happen unless I travelled North on vacation.  Seeing it was the best, I just wish my wife was there to share it with me (she was in bed keeping an ear open for our 2 yr old daughter).

Since then I have put back together my Canon 40D.  It works fine with manual focus  (modification without filter removal means auto focus is slightly out of focus) but cannot be connected to a computer since it lacks a USB socket.  Maybe one day I will get a change to capture this great sight with that camera and I will hopefully be a little more prepared!