Practice Session - Orion Star Trail from Silchester Roman Camp

[Kenny]

An evening of expirmentation with my (new) Canon EOS 760D DSLR as I hadn't done any serious astrophotography for a while and am still large unfamiliar with this camera since replacing my 450D.

On 25th November, I drove out to Silchester Caleva near Mortimer Southwest of Reading, which wasn't as nearly a dark site as I remembered it to be when I used to lead the Reading Astronomical Society observers out there. I could only see 9-10 stars inside the 'square' of Orion!

13 x 2 minute subs @ 18mm, f/5.6, ISO200, facing Orion as it climbed out from the horizon.

Unfortunately, the dew heater I had ordered from Belgium didn't arrive until the next day so I can see in the individual subs that, over time, the lens started to mist up with condensation but I stacked them anyway and it has produced an interesting effect where the star trails near the eadge of the lense fade out towards the end of the trails.

I tried stacking with Startrails.exe but the result was poor quality. Instead, I pre-processed the individual subs in Lightroom, exported them to Photoshop as layers, and combined the into s single flat image. I then re-processed in Lightroom to generate this interesting and colourful result.

I made no end of mistakes on the night not least of which was not removing the protective UV filter and not focusing properly.. I also didn't take any flast or darks and didn't process out the hot pixels. I also found the new flip-out touch screen to be far to bright for astronomy on it's brightest setting and far to dim for focusing on its dimmest setting. However, it was a good practice session to remind me of some of the skills I was starting to forget.