Very Amateur Astronomy

Taking any brief window for imaging as I am at present I managed to sneak an our of clear skies to take a few more images of M42. Guiding for once was working very well after adjusting the counter weights a little. I managed about 33 minutes of data. Each frame being 3 minutes at ISO800, aligned  stacked in Deep Sky Stacker and processed in pixinsight. The Moon was nearly full which reduced the image quality and my exposure time. For some reason I had a lot of colour issues when stacking in Iris, probably due to the addition of the CLS CCD filter. I will need to look into how to resolve that in future.

A slightly different processing from a stack with different options :

Imaging Setup

• Orion Optics 250mm F4.7 Reflector
• Vixen Sphinx SX Mount
• Canon EOS 1000D unmodified
• Astronomik CLS-CCD Filter

Guiding

• Vixen A70LF F12 Refractor
• Modified Phillips SPC900NC webcam
• 0.6x Focal Reducer
• Guidemaster

Images

• 11 x 3 minutes @ ISO800
• Darks and Flats x 15 each
• Aligned and Stacked in Deep Sky Stacker
• Processed in Pixinsight

It’s been a long road over the summer to get to this point, but I think I finally have this particular nut cracked. This is a single 6 minute frame of the Orion Nebula, unprocessed, washed out by the moon and as it arrived off the camera.

I’m pretty happy with that, it’s not perfect, there is a slight stretching of the stars. But this one one of 10 test images and they were all of equal or better quality. The stretch is along the RA direction which means the likely causes are periodic error and over correction by the guide software. The dec axis is working beautifully despite it’s frustrating backlash.

Experimentation has shown me that the automated aggression control of guidemaster doesn’t function very well on this mount, disabling that option helped enormously.  Adjusting down the RA autoguide movement speed also reduced the stretch. The next testing step will be to do the PEC recording, however Vixen really need to improve PEC on the starbook, I don’t want to have to do it every time I want to do some imaging!

This is addition to my previous post really, as I had taken more images that I had not processed on Tuesday night. First off though I found my missing mosaic video section! This means I’ve been able to complete the image properly now, without the missing chunk. I’ve also left the colour in and applied a small gausian blue to smooth off some of the sharper edges.

The other data I wanted to process was a set of 30 full frame raw format images of the moon taken with the canon 1000D. These were then stacked in registax, tweaked with wavelets and then dumped out to gimp to adjust the colours. In this case I pushed the saturation levels right up, this brings out more of the subtle changes in the moons surface that the human eye really only see’s in shades of grey but the DSLR picks up.  It’s an effect that I really enjoy and not possible with the mosaic above where every individual section has it’s own balance and variation.

We had a clear night!

No joking, it was clear, in England all night on the 30th, and properly cold as well. It’s been so long since we had a good clear night that I had the roof off the shed just as soon as I could get out outside. The only real damper on this otherwise perfect evening was a big bright moon, which of course ruined any chance of me doing any deep space work. But I have a webcam, and I have EOS movie record, so I figured I would make the best of the night and try my hand at some lunar imaging.

The first thing I wanted to try was capturing a few minutes of video from the Canon 1000D using EOS Movie Record. I set that up and left it running whilst I got myself sorted for the night. A few minutes in I noticed a flicker on the screen from the corner of my eye and made a mental note to check it the next day. This is what I found when I reviewed the video :

So that was a bit of pure luck on my part, but it makes for a striking image I think.

Next I setup the webcam on the 250mm reflector to try my hand at lunar imaging. At first I thought I would just stick to one area but after a little while I had started to collect connected sections, and from then on it turned into an attempt at a mosaic. This was my first attempt doing this and unplanned so naturally I missed a bit, which I shall kick myself for later.

• Philips NPC900NC
• Baader UV/IR cut filter
• Orion Optics 250mm reflector

The image is composed of 27 individual frames, each of which came from a 1000 frame avi video, the data was captured with k3ccdtools and stacked in Registax.

In order to build the complete image I first spent a long time in photoshop and came out with something I was happy with. Then out of interest I tried the photostitch tool in Windows live photo gallery. In about three minutes it had aligned, colour corrected and stitched the whole image together far better than I ever could. I was really impressed as about a third of the frames were at an angle compared to the rest due to the scope reversing half way through. So if you have images to align, give it a go, you don’t need to do anything more than select the images and click go, it works out everything else by itself.

The full scale image is some 3360 pixels across and I shall locate some hosting for that soon.