Pursuing the Perseids

This all started back in 2015. I watched a video by a guy called David Kingham who is an astro-photographer based in the USA. He showed how to photograph the Perseids meteor shower and produce an image where all the meteors appear to be coming from one region of the sky. It was an amazing photograph and I wanted to achieve the same affect myself. Little did I realise how challenging it would become.

The Perseids meteor shower is the second best display in the year and occurs in August when camping outside all night is a lot more tolerable than in winter when the best, the Geminids, occurs. It is caused by the dust trail of comet 109P/Swift-Tuttle which last passed through our system in 1992.

Meteor showers are named after the constellation nearest to where they appear in the sky. This point is called the radiant and it moves through the night as the earth rotates. So if you photograph all night long, you end up with lots of images where the shooting stars appear randomly from various directions. But the Perseids appears quite close to to the pole star which makes it relatively easy in post-processing to rotate each image around the pole star to a single point in time. This effectively cancels out the rotation of the earth and gives you an image where most of the meteors appear to come from the radiant. I say 'most' because you can always get random meteors from any direction as bits of space dust get caught in the earth's gravity well. And the radiant isn't a precise point but more like a region of sky.

So I first tried to photograph the Perseids in 2015. I had selected my ideal location as the Lairig Ghru in Cairngorm which lined up with the radiant giving what I hoped would be a great composition of the River Dee in the foreground, Devil's Point in the mid-ground and the Perseids as the third element of the shot. I had done a reccy of the location a few weeks before and identified my camp location. I cycled in carrying much of my camera gear in a rucksack along with panniers. The last bit of the trail was very rough and I broke one the panniers resulting in some temporary repairs being required.

With tent and camera quickly setup I started preparing my tea just as the wind dropped and a cloud of midgies descended on me, my camera and the food. Freeze dried food is pretty tasteless at the best of times but eating while wearing a midge net knocked a couple more stars off the restaurant review.

Midges are relentless critters and the only solution was to hide in my tent and hope they didn't devour the camera which I left ready to shoot.

For the photo gear geeks this is a Canon EOS 5D mk2 with a Samyang 14mm f2.8. The bright red thing is a lens warmer which prevents the lens fogging up with overnight dew, essential on any night in Scotland if you're hoping for clear skies.

I grabbed a couple of hours sleep before emerging from my tent approaching midnight to clear skies and started the camera shooting using an intervalometer (thing that keeps pressing the shutter button electronically so you don't have to). Twenty minutes later the cloud rolled in and obscured the night sky for the rest of the night. I'd managed to capture one shooting star.

The trip wasn't an entire waste of time. I'd managed to take a reasonable evening lanscape shot. Not what I was after but better than nothing. You can see the idea of the composition I was looking for. That's Devil's Point on the left and the v shaped Lairig Ghru would have balanced the shot nicely.

I also learnt a few things from the experience:

  • I hate midges.
  • Banking on a single location in Scotland is unlikely to work out. I'd need to be more flexible and have several options ready depending on weather conditions and cloud forecast, preferably all with great foreground aligning with the Perseid radiant azimuth.
  • Carrying lots of heavy photo gear on your back whilst cycling isn't safe both for the cyclist or the camera gear.
  • Freeze dried camping food sucks.

I made no further attempts for four more years due to a combination of lack of planning by me, work, family commitments or plain old lack of motivation. But I still had that shot by David Kingham in mind. So late in 2019 and through most of 2020 I scoured OS maps looking for the perfect alignment of landscape and sky. Another factor to consider was that the peak of the meteor shower occurred on the night of the 12th / 13th August which coincides with the start of the stalking season in Scotland. So heading somewhere that had a lot of shooting butts marked on the map or was known for its stalking was adding additional risk of being asked to go elsewhere even if I was only planning to be there at night. I settled on four locations covering the corners of the compass but I also had a plan B which would be just to head somewhere dark with a good view and pitch the tent. This would then provide the classic 'lit tent in the foreground' shot.

I became very familiar with the Photopills app which is soooo useful I wonder how I'd manage without it now. I'd also invested in a lighter Canon M6 mirrorless cropped sensor camera which isn't the ideal tool for this type of shot because of the extra focal length effect but it was lightweight and so easier to carry. I added a relatively cheap manual everything Samyang 12mm f2.0 lens which gave an effective focal length of 20 mm. Not ideal when you're trying to capture a large piece of sky, but with careful alignment of the camera and with help from Photopills I reckoned I might just be able to do it.

One interesting fact I learnt about meteor showers is that you get more meteors after midnight; why? Because before midnight you are in the lee of the rotation of the earth around the sun. The earth goes around the sun in an anti-clockwise direction when viewed from above the north pole and it rotates on its own axis in the same direction. So if you visualise the earth sweeping through a cloud of dust, then it will pick up more of that dust on the leading face as it rotates around the sun. Because it is also rotating on its own axis, the leading face is always changing and it's only after midnight (no daylight saving time applied) that you are on the side that is on this leading face.

However, the meteor forecast for 2020 was going to be affected by moonlight. The predicted peak number of meteors would occur on the night of the 12th / 13th August and the moon would rise shortly after midnight.

So you can see from the graph here that the predicted number of visible meteors is increasing until the time at which the moon rises where it takes a sharp decline before it resumes an upward trend until dawn washes out any chances.

Of course I hadn't expected a major worldwide virus pandemic outbreak to occur in 2020. Fortunately lockdown had eased by the beginning of August. I also planned to put my campervan on a campsite as my basecamp and venture out to shooting locations by bike and camp / bivvy under a tarp overnight. That approach minimised need for social contact whilst also putting a bit of much needed income back into a local business.

I had booked the week of the 12th August off work but as it neared, the long range weather forecast wasn't looking promising. The nights before and after the 12th / 13th weren't predicted to have as many meteors but those predictions are just based on past statistical data. It's a bit hit and miss whether you get a good night or not. Plus the latter part of the week would be better given that the moon was rising later and later each night so I was still hopeful.

The first part of the week was a cloud fest but several weather models were predicting a good chance of clear skies in Dumfries and Galloway. Which was kind of handy because that was one of my preferred locations and it also contained the Galloway Dark Sky Park so looking good for minimising light pollution and little chance of being mistaken for a pheasant and shot as I planned to photograph from a hill outside of any stalking areas. I booked my campsite (got the last available spot) which was really busy because Covid was concentrating the holiday season into very short period. Then I began to convert the pile of photo and camping gear strewn about my floor into some semblance of order.

One of the extra challenges facing me was my latitude. Between the spring and autumn equinoxes the period of darkness gets shorter the further north you go. Consequently the further north you are, the fewer number of meteors you are likely to see. Of course that has to be balanced against the light pollution which is higher in parts of England due the greater population density. So Galloway had another factor in its favour for me compared to venturing north of the central belt.

Of course getting to my intended location wasn't going to be that easy. The Tuesday night produced an almighty electrical storm; there was thunder and constant lightning during the Tuesday evening but it really got its act together in the early hours of Wednesday when I was trying to avoid becoming sleep deprived before several days of probable sleep deprivation. Then after a poor night's sleep I discovered the internet was off. Chances were that it was a central issue rather than my router but it took me a couple of hours to verify that. Which put me behind schedule but at least it gave time for the flooding and ensuing traffic chaos to sort itself out.

I got checked into the campsite early afternoon and then set off on my eBike (another upgrade from 2015) for a quick reccy of my planned shoot. Due to lockdown and also not being exactly sure which part of the country was going to be clear, I hadn't had the opportunity to reccy my preferred locations.

This proved to be a bit of an issue when after 6 miles of hard cycling (yes, even on an eBike) and 1200 feet of ascent I reached a deer fence. Such fences are a real pain if you have an eBike because lifting a heavy bike over them is virtually impossible. There was a kissing gate in the fence but without cutting my bike in two it wasn't going through. So I parked the bike up and set off for the remaining mile on foot. The thought of coming back later and lugging camping and camera gear over that mile wasn't appealing.

However, after I reached my planned shooting spot and confirming it was good, I also spied a couple of vehicle tracks running on the other side of the fence I had previously crossed. Following the tracks led me back close to where I'd left the bike. It would be a bit boggy but definitely doable. Plan A was back on !

A rapid descent back to the campsite, I grabbed some food, a quick shower and then loaded up the bike for the return trip. Adding several kilograms of camera and camping gear does make for a really heavy bike. But the eBike just got on with it. The ascent ate through the battery but I had plenty spare by the time I reached my shooting location and even more importantly I wasn't wet through with sweat or needing any recovery time.

I had arrived just as the sun was setting. Ideally I'd have been already in place and setup about an hour earlier but storms and the Forestry commission's deer fencing policy had been against me.

A quick brew and some more food and I was then ready. I was in just a bivvy bag, no room for a tent but it was really warm at about 20C so not a problem. I could sit and keep an eye on the camera whilst enjoying the view and a cuppa. Bliss. Not a single soul about as I sat back and waited for the show to start.

And waited.

And waited.

The problem is that watching for meteors is actually quite boring. Humans aren't good at staring at a dark piece of sky for long periods with nothing appearing to happen. Yes it's a really great experience and fantastic when you see a really bright meteor but there were so few that night that I even checked I was looking in the right direction.

There was also some high cirrus cloud that wasn't helping the chances of any good images.

Sometimes the meteors are there but so faint that only the camera picks them up. But later on after checking I found only a couple of images with meteors but loads of satellites and aircraft which are easy to mistake for meteors if you don't know what you're looking for.

This is a good time to explain how you tell the difference between a satellite and a meteor. If your photo exposure time is say 20 seconds and the trail appears on multiple sequential images then it isn't a meteor. Meteors last no more than a second so anything that's around longer is going to be either a satellite or a plane. Planes usually have flashing lights which will give a dotted appearance on a long exposure image.

This is an aeroplane

Satellites normally produce a very thin constant light source unless it's tumbling in which case it may increase and decrease its brightness over a long period.

This is a satellite

Meteors normally produce a streak of variable thickness, brightness and colour. Yes, meteors are coloured. I never realised this but they go through blue, green, yellow, white and sometimes there's a tinge of orange as they burn up. I've even seen some beauties leaving a smoking trail.

This is a meteor

During the storm on Tuesday night I'd added a new app called "Lightning" to my phone's weather app collection (you can never have enough weather info). The thought had crossed my mind that being up a hill, not far from a wire fence and having a metal object atop a tripod right next to me might not be a good idea if a storm were to come my way. There was also a mobile phone mast at the top of this hill; not sure if that was likely to attract lightning or not. I remember from O Level Physics that lightning conductors on tall buildings actually reduce the frequency of lightning strikes. But I wasn't going to bet my life on a 40 year old memory of a physics class that was probably glossing over some significant details that meant it didn't apply in my situation. But it did mean I was getting a good data signal which allowed me to keep an eye on any storms in the vicinity.

At about midnight I noticed the unmistakeable flash of lightning away to the south of me. There was no thunder so I knew it was still far away but still a concern. I checked the weather radar and lightning apps; Cumbria was getting it and after watching for a while it was clear it was moving north towards me.

In this picture the red dots are the lightning strikes and the blue dot is me. The nearest red dot is about 50 km away.

I've only ever been on a mountain in an electric storm once before; it was the most frightening experience of my life and not one I wished to repeat, especially at night and alone. So I was getting a little nervous when another much brighter lightning flash occurred due east of me. The strike didn't appear on the lightning app but I wasn't going to ignore the evidence of my own eyes; it was time to go. I knew packing up camp in the dark wouldn't be easy and I'd need to take take extra time to ensure I didn't leave anything behind. Then I had at least 30 mins of walking the bike down through the boggy bit and past the deer fence and into the relative safety of a forest.

Once back onto forest fire roads I took my time descending and concentrated on not getting lost. Bike lights as bright as car headlights helped dispel any remaining fear and allowed me to spot a hare and a hedgehog; always good to see those guys about. I was soon back at my van where I tried (probably unsuccessfully) not to wake my neighbours.

Of course the storm never arrived overhead. Not sure where it went because once I'd had a cuppa, I was off for some kip. I was disappointed yet again to have failed to capture the Perseids but I had booked two nights at the campsite and the weather forecast for Thursday night was much better....there was still hope.

After only four hours sleep I woke to a beautiful morning and realised there had been no storm. I couldn't get back to sleep, so I started thinking about what to do for Thursday night. Whilst I could stick to my original planned shot, I'd got a bit fed up going up that particular forest track and was looking for something a little easier to get to that didn't require pushing my bike anywhere. I soon focused in on the nearby Southern Upland Way - a walker's route but might be accessible by bike in sections. Even better there was the Hill of Ochiltree which had a trig pillar. Why did the Ordnance Survey put trig pillars at the top of hills? So they could get a good view to the next trig pillar sited on another hill when they were doing the triangulation of Great Britain. Just what I wanted. I like trig pillars - they've been around all my life and are one of the most welcome sights a hill walker can see when lost in cloud or when slogging up to the top of a Munro.

After a bit more recuperation, food and a bit of gear sorting I set off in blazing sunshine to reccy my plan B. No fences were found and an easy cycle to a fairly flat summit so good for camping and the trig pillar was still intact and so served as a handy bike rest.

The handy bike rest and the Photopills augmented reality view of the predicted Perseids location in the sky tonight

A quick check with the Photopills app confirmed a good clear view and a potential composition using the trig pillar or I could use the lit tent in the foreground. Plan B was on!

I returned later giving myself plenty of time to get set up and ready. I was using a tarp for a shelter rather than a tent. This makes it easier to access the camera and also allows you to enjoy the view, you literally do sleep under the stars. The disadvantage is that there is no hiding place from the midges and it can get a wee bit cold although you get some shelter from the wind and any dew.

Of course the wind dropped whilst having some food so eating with the midge net was required again. I'd also selected Tesco's sausage casserole for dinner which proved equally as tasteless as freeze dried food. I'm still searching for decent camping food.

I had the place to myself although some hill walkers doing the Southern Upland Way were camped in two tents about a kilometre away. Thankfully they stayed away and didn't join my campsite as I don't think they would have appreciated the noise of me climbing in and out of my sleeping bag through the night.

I gave up on the shot with the trig pillar favouring the lit tarp in the foreground approach. The challenge with this shot is that if you're going to use the tarp as shelter during the night then you'll be in the shot all night. So you have to be careful where you point any torch light and avoid standing up blocking the sky. So each time I left the tarp to check the camera I had to crawl out of shot before standing up.

When I started shooting it was still quite light so my exposure time was short. As the sky darkened I lengthened the exposure time and increased ISO until I stabilized at about 20 seconds with 3200 ISO. As before, I was using a lens warmer to prevent the lens fogging up which was powered from an external battery which also supplied the camera.

It soon started to get cold, the forecast had said 12 degrees C, but it felt much colder and I was soon realising my mistake of only bringing a light sheet sleeping bag inside my bivvy bag. I was wearing everything I had and had the bivvy zipped up as much as possible without suffocating myself. At about midnight I also realised my sleeping mat was deflating and required several re-inflations during the night. At least it kept me awake which meant I could start reducing the exposure as the dawn approached.

I knew the moon would rise half an hour after midnight. Lying in my bag I first saw it appearing like a red candle flame in the grass. Once above the horizon the moon was less than one quarter full but after several hours of darkness my eyes took a while to readjust to the brightness. I had to adjust the camera exposure again too.

Later I think I made another exposure change and blew up my mat for another 30 minutes of freedom from ground chill but to be honest by 4 am I was cold, very tired and not really with it anymore. Either I fell asleep or passed out just before 5am. Looking at the images afterwards I can see that the battery also gave up at 5:21 am but the images for an hour prior to that are very overexposed.

I awoke with a start at 6 am not realising the time and ran to the camera to make a change. It took me a minute to work out that a) the camera was dead and b) the sun was up. I had no idea whether I captured any meteor images but I had nearly 1200 images on the card.

It was a lovely morning and I momentarily contemplated having some breakfast as I sat and watched the sunrise. Then I remembered that I hadn't brought any breakfast. I still wasn't really awake.

So it was a quick pack up and an easy downhill ride back to the van or so I thought. The warmth of the sun had also woken about a zillion midges. Cycling through a cloud of midge at 20 mph is a unique experience; one that required the use of eye protection and a mask to prevent ingesting them up the nose.

Back at the campsite it was no better; they were really hungry and I was on their breakfast menu. So I sought shelter in the van and waited for the sun to force them into hiding. The midge lives a perilous life and being so tiny is in constant fear of dehydration from strong sun. Too windy and it can't fly. But cool damp calm days are its prime environment.

I used the midge downtime to back up the images, shower and get some breakfast. I still didn't know if I'd got any good meteor shots and decided not to look until next day. Instead I'd just enjoy the rest of the day as there was nothing more I could do.

The resultant image took several hours of post-processing largely because I included all 28 meteors that I'd captured; some are so faint that I should probably not have bothered but after all that effort I wasn't going to delete them now. The final images comprises of over 30 layers and is 5.3 GB in size.

I'm pleased with the result. The meteors aren't as big and bright as I'd hoped so there's room for improvement next time . . . next year . . . maybe.

Tim Hodges. August 2020 www.irisone.co.uk