Thursday, 16 July 2020

Catching a Comet

Catching a Comet

Comet C/2020 F3 NEOWISE

Some years ago, I remember standing under a clear sky on a campsite in Swansea and staring up at the site of comet Hale Bopp.  Back then, digital photography wasn't really a thing.  Camera smart phones were still some years off, and astrophotography was still really in the realms of research institutes or those who could afford it.  For the masses, you relied on visual observations and if you were interested in sketching, drawing your observations for your own records.  Some would capture the image in photos using the SLR cameras of the day.  This really wasn't that long ago.  1997 in fact.  It was haled as the best comet visible from Earth for decades.  Since then, any time a comet has come close to being visible, it has been compared to the Hale Bopp comet of 1997. Unfortunately, nearly all of them haven't lived up to expectation, especially becoming naked eye visible.  The problem is, comets are really unpredictable.  Often, they are only discovered a matter of weeks or months before they pass on their closest point of their orbit to the sun and pass their peak brightness.  Sometimes, comets don't make it past the Sun, and are torn apart and other times, they quickly fade away.
So when word started coming out of a new comet discovery came about a couple of months ago, the usual chatter of attempted predictions on it's brightness started.  Personally, I wasn't even aware of it.  That was until a flurry of social media posts and news articles started to reference it's brightness started to appear.  It was then that things started to get exciting.

Time to Image

I've never had the opportunity to image a bright comet before.  I've imaged a very dim comet through a telescope before, but that wasn't amazing.  So when I learnt that people could image the comet with a simple DSLR I put myself on a quick YouTube crash course on how to go about photographing the comet.  Now all I needed was a clear weather window, and a time when I could get out under the night sky.  For once, timing couldn't have been better!  The comet was always going to be low on the horizon.  I also had to contend with the time of year.  Being Summer time, the sky doesn't get truly dark.  In fact, astronomical darkness is still some weeks away where I live.  So, I had about an hour from around 11.00pm onwards when it was dark enough to see and image the comet, but before the comet dipped too low on the horizon.  If I missed that window, I would need to try again around 2.30am as the comet would slowly rise above the horizon again, but before the Sun would also start to rise and cast dawn daylight across from the East.
To get to a place where I could see the northern horizon would mean leaving the house and a trip on the mountain bike.  I packed up all my camera kit and tripod, fitted the bike lights, grabbed the head torch and off I went into the darkness.  
My choice of location couldn't be less glamourous.  But it served it's purpose.  I set up on the edge of crop field on the bank of the River Wye, within 30 meters of the sewage treatment works.  With the gentle hum (and the other hum) and the occasional clank as the treatment works did their job, I set up and started to do mine.  So, here we go.  A collection of images from two evenings from the same location.  All the images were taken with my Canon EOS 1100d camera and the standard lens kit that comes with it plus my widefield Samyang lens.  There were no filters used at all, and only some light touch-ups made with GIMP in post processing.  I hope you enjoy.

f/5.6 iso 3200
5 sec 180mm

f/5 iso 100
4 sec 75mm

f/5.6 iso 1600
6 sec 180mm


f/5.6 iso 3200
6 sec 125mm


30 sec iso 400
50mm


iso 1600 30 sec
50mm