Andromeda


Pentax 645z with 120mm f/4.5 lens
130 seconds @ f/5.6 @ ISO 12,800 

Astrophotography is unlike almost any other photographic pursuit. 99.99% of the time the subjects being photographed are identical to those photographed by anyone else. With the exception of meteor showers and eclipses, a deep sky or planetary photograph that I take today will be of a subject that is essentially identical to that photographed by someone else on any other day.

So why bother?

Strange as it seems, there is still something compelling about producing a successful image, and both the difficulty and the pleasure of the process is undeniable. 

Not long previous to this I published an article on LuLa about doing deep sky astrophotography with the Pentax 645z and iOptron SkyTracker. As luck had it, for several weeks following there were no clear skies, or if they were clear they were dominated by a full moon, which washes out the Milky Way and other deep sky objects.

100% Enlargement

As good as the SkyTracker is for doing this type of shooting, because it isn't a true telescope mount and doesn't have setting circles or a GoTo system, finding specific objects can be a challenge. I was very keen though to capture one of our nearest galactic neighbours – Andromeda (M31)

Located 2.5 million light years from us, Andromeda is a spiral galaxy much like the Milky Way though roughly twice as large. It contains 1 trillion stars. The Milky Way must look very similar to anyone there looking in our direction. The smaller galaxy about 1 degree north is M110 and the one just to the south-east is M32.

Using an App called Redshift I knew roughly where to find Andromeda, but it is located in a relatively empty part of the sky, and there are few landmarks. I was lucky though, and Andromeda turned up in my first test frame.


raw file

A two and a half minute exposure tracked perfectly using my 120mm lens. I didn't use anything longer, because A: I wasn't sure I could find Andromeda with a long lens and no setting circles or computerized drive system, and B: I actually wanted a shot that showed the galaxy floating on a large field of stars. 

A longer exposure would have shown more of the faint outer regions, but the core would have burned out even more. It takes a large scope and sophisticated imaging stacking techniques to produce images much better than this. My next experiments will be with stacking.

Because of the very high resolution of the Pentax 645z's files, along with its clean high ISO, a 20X25" print of this image is arresting to see. I have more colourful deep sky images, but the simplicity of this one, along with the satisfaction of know that "I made it...", means that I'll be hanging a large framed print of it in my office shortly, something that I don't do that often.

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If you click here, or on the image at the top of this page
you will download a 3 Megapixel JPG. This is made available
for your personal use only and may not be reproduced in any form
online or on any other media without expressed written permission.
You may make a print of any size for your own personal use.
© 2014 Michael Reichmann

Please note that at 100% on-screen you will see the reality of both
inevitable lens imperfections and air turbulence.

Do make a print though, as I think you'll find it of interest. 
The file displays the capability of large sensor / high ISO astro-imaging,
done without image stacking or the use of specialized processing software.

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This image and its analysis may be discussed on the LuLa Forum

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