Sunday, 19 February 2012


So I'm trying to get into astrophotography. I thought it might be worthwhile to document my progress here, successes and failures both. We'll begin, predictably enough, with ignominious failure. But first a bit of background.

I was a professional astronomer for a large chunk of my life. I studied astronomy, gained a PhD (in the course of which I wrote and published three papers on the velocities of binary stars). After that, I worked in Holland. Apart from a two-year stint at Utrecht University, all of my employment was within the European Space Agency. During that time I worked on many projects, relating to both space and ground-based astronony - and published many more papers. My research interests broadened from binary stars to compact accreting objects, such as black holes, pulsars and white dwarves. Along the way I also worked on distance determination to quasars and spectral studies of ordinary stars. By the time I left, in 2004, I'd been lucky enough to not only have a career in astronomy, but to visit some amazing places and meet some extremely smart people, including some true legends. But that, more or less, was it for me. I didn't fall out of love with astronomy but after I quit, I certainly felt the need to get away from it a bit.

However, before all this professionalism, I was also an amateur astronomer. My parents kindly bought me a telescope when I was 16, and it changed my life. It was a small but capable refractor, and I still have it, and despite an unscheduled trip to the bottom of the stairs after a pub crawl, it still works very well. I now have two other scopes. The first of these was a partially dismantled and damaged reflector which a colleague of my father's thought I might be able to make something of, but unfortunately I was never able to. I'm interested in astronomy, and many astromomers are also gifted and enthusiastic at tinkering with optics and mirrors, but that's never been of great interest to me.

My other telescope was a gift from my wife. I've had it for about 15 years now; it's a Celestron reflector with a 9 and 1/4 inch mirror. It's a beautiful thing, and just within my capabilities to handle unaided. We looked at the 11 inch model, but I'm glad we didn't go for it; that extra weight makes a big difference when you've got to move things around in the dark.

It's not a "GoTo" scope. It has no in-built GPS or computer control, unlike many models now on the market- merely an equatorial mount and a Right Ascension (RA) tracking motor. But for all that it's very easy to set up and use - even with the scope de-attached from its tripod, I can be up and running in about five minutes. When I moved back to Wales, I set the elevation of the equatorial mount to the latitude for my part of the UK and haven't touched it since. A telescope must be polar-aligned for correct tracking of any astronomical object, which means finding true north and ensuring the scope is lined up along that axis. If Polaris is visible that's easy enough, but I've found that the front of my patio is close enough to the East-West axis that I can simply get away with lining up the front two legs of the tripod against the patio's edge. If I line up on Jupiter, or any other object, the telescope will keep it centered in the eyepiece for many tens of minutes, which is - or has been - good enough for me.

I've been using the Celestron quite a bit lately. I don't know whether this is due to me feeling enough "distance" from my professional career that I can just enjoy astronomy on its own terms again, or the consequence of a spate of clear nights this winter, or the fact that I've had contact with a number of astronomical societies in recent years, or even the "Brian Cox effect" (yes, I like Brian, I think he's good, and I've watched and enjoyed his programs). Whatever, the Celestron has been getting more use. And inevitably, since I am also interested in photography, I've been thinking about taking pictures. After all, why not? It's perfectly possible to enjoy the night sky, or indeed any aspect of nature, without being able to record what you're seeing - I get tremendous pleasure out of just looking at birds and animals, let alone photographing them. But, photography undoubtedly brings its own pleasures - and challenges.

With this in mind, I began looking into the possibilities of adding a camera to the Celestron. While there are a number of relatively inexpensive webcam-based imaging devices on the market - Celestron do one - it quickly became clear that these are really only good for the Moon and planets. These units cost around 100 - 150 pounds so are quite reasonable assuming you've already spent several thousand on a decent telescope (I'm not saying any of this is cheap). At the other end of the scale are high-end imaging systems costing thousands of pounds themselves. Obviously, it would have been a very bad idea to jump in at that end of the market, especially when I'm not blessed with particularly clear or dark skies most of the time. With those low and high-end systems ruled out, there seemed to be two possibilities: use my own digital SLR, with an appropriate mount, or invest in a mid-range astronomical camera with the capabilities to work on both planets and deep-sky objects. From what I could gather, there's a steep learning curve involved with SLR photography, and I liked the idea of being able to see what I was doing in realtime, via a laptop. So, I splurged on a complete camera kit from Optic Star in Sale, Manchester. The system I bought was this one, the DS-336C XL. Importantly, the kit came with all the bits and bobs I'd need to get going: an adaptor tube to connect it to my scope, cables for the laptop and optional power supply, and some software.

I installed and tested the basic software and verified that the camera was functioning, although as yet not plugged into the scope. he kit also came with Nebulosity, a sophisticated piece of imaging software, which unfortunately I can't get to run due to a problem with the C++ libraries on my laptop. I'm sure I'll get there in the end, though. Unfortunately a period of miserable weather clamped down on us and it was only last night that I was able to snatch an opportunity to try my first actual imaging run.

Jupiter is still visible in the early evening so this was my objective. I set up the scope, and used a normal eyepiece to lock onto Jupiter before it hid itself away behind some nearby trees. Even with the scope just out of the house, the view was excellent: all four Galilean moons on display, and at least two prominent bands on the face of Jupiter itself. I then swapped the eyepiece for the camera, plugged the camera into the USB port on my laptop (which was balanced on a kitchen stool out on the patio, next to the scope) and started up the imaging software. What I got was a blank black rectangle.

Nothing. No Jupiter, no moons.

However, refusing to be daunted, and knowing that my finder scope - the little scope on the side of the main one, designed for target acquistion - isn't perfectly aligned - I tried hunting around a bit in both DEC and RA. Quickly I found a big colourful doughnut-shaped blob just out of the field of view. I centered this blob and then tried adjusting the focus (A doughnut or ring-shaped image almost always means you're out of focus. Unless you're looking at something doughnut or ring-shaped). To my delight, the object not only became sharp, but it was accompanied by four smaller blobs - the moons of Jupiter. What I couldn't see, yet, was any sign of banding. Jupiter looked white, suggesting (to me) that I needed to turn down the camera's exposure, whatever the hell that meant in the context of an imaging system. However, out in the cold and dark on the patio, I couldn't figure out what I would need to do. What I could do, though, was save frames from the image. I did this, and could even see the path on the computer where the saved files were supposed to end up. I figured this would be an acceptable first step into astrophotograhy - the acquisition of a in-focus, if over-exposed, image of Jupiter and its moons. Suitably enthused, I then swung the scope onto a couple of other targets, including M42, the nebula in Orion. All I could see on the screen, though, were stars. Oh well, early days.

When I got back indoors, though, I couldn't find my saved files. They weren't where they were supposed to be. I played around with the settings and found that I could save individual frames onto my desktop, but not into the C> Program Files > directory that the system seemed to want to write to. Presumbly some permission or other was preventing it from saving the files there. No biggie; I'll know better next time. I also did not succeed in getting the software to save multiple frames; you're supposed to be able to tell it to save a given number of frames and off it will go, but I was not able to save more than a single frame at a time. I think, anyway. One thing I'm mindful of is that my professional background may be both a help and a hindrance here - I could be bringing to bear some assumptions that simply aren't valid. It's a learning curve, in other words.

As I said, I did not manage to save any files from last night's observing run. But given the success rate of my first dip into astrophotography, it seems entirely fitting to present this completely blank (indeed, none more black) image, which was one of the test files I generated yesterday:

Beautiful, isn't it? A sight to stir the soul. The glory and wonder of the cosmos, laid bare. In all its extreme blackness. Frankly, I hope to do better next time. Meanwhile, if anyone out there is into this stuff, feel free to chip in. I'm sure I'll learn something.


  1. I hear you. I'd have similar problems with imaging. Be glad your focusing experience was as simple as it was. I had to buy an extension tube. And I've had the same problem with the imager not being pointed at quite the same place as the center of the eyepiece.

    But, it is alluring. I often just attach my dSLR piggyback on my scope and take 30 second exposures with a old 50mm 1.8 lens. It is STUNNING what you see. You get lots of little stars that you can't find on any normally available star charts. That just kinda blows my mind....surely they have a name, but they're so dim that no one bothers to put them in even the charts going down to magnitude 12. And, you start to see galaxies and stuff like that. It's really amazing. Plus....there's no nonsense with that sort of imaging. It's like doing your own deep sky survey.

  2. I should probably have a look at piggybacking; sounds as if there is very little to go wrong, and I know my way around an SLR well enough.

  3. My forays into astrophotography have resulted in all sorts of jet black images. I blamed it on my equipment then and will continue to do so for the foreseeable future.

  4. Perhaps you should try taking some images during the day while focused on a distant object. With my limited imaging attempts I found that it was easier to familiarize myself with the capture software that way. In the dark it's much more difficult to try to figure stuff out.

    Once that's sorted you'll have to get well acquainted with finding and focusing on the objects. Since the eyepiece and camera doesn't seem to be par-focal in most cases, and the FoV differs, that's another 'fun' experience.

  5. I have been interested in amateur astronomy for years without ever having the funds to do anything about it. This kind of post reignites that passion, I can't wait for the next steps.

    A friend of mine had a fancy Meade scope and viewing anything other than the moon through it was really disappointing to me.
    I would love to see what is possible from an astrophotography point of view on a mid-level budget.

  6. I thought you were pulling my leg for a minute, I could see lots of blobs and star spattered patterns, then I cleaned my monitor screen. Ha

  7. The clear skies this winter (I'm near Bristol) have also enticed me outdoors to try a bit of astrophotography. I have a 4" Celestron but have been very disappointed which the results of attaching my DSLR to it with a T-Ring. I never seem to be able to photograph why I can see in the eyepiece! While I've captured some nice lunar photos and some of a partial solar eclipse a few years ago I've never been able to get a photo of any of the planets.

    So this Winter I invested in a cheap but reasonably sturdy camera tripod and tried my hand at some wide angle timelapse photography. So far I've only been able to capture 17 30 second exposures before my software crashes which is quite frustrating but the images look promising. I'll keep persevering.

  8. Congratulations! You've managed to take a marvellous picture of the default state of the universe.