How time-lapse photography works in the study of glacial processes

PhD update: November 2016. Whilst preparing a talk for the Geography research seminar series at the University of Manchester, I decided to include some information on time-lapse methods in glaciology to help introduce the topic.  Within this, I wanted to convey how different glacial processes were visible at specific image intervals. By constructing image sequences with various intervals, I could effectively show the processes that occur at the front of glacier and how different processes operate on different time-scales.
A time-lapse camera installed at Ultunafjella, overlooking the calving front of Tunabreen (August 2015)

One of our time-lapse cameras looking at the calving front of Tunabreen, a surge-type glacier in Svalbard. This camera remained here taking photos every 10 minutes between August 2015 and September 2016. This camera collected 24,136 images in total.

To begin with, we take a camera and place it in front of the glacier we wish to study. Using an external timer (or intervalometer), the camera can take photos at a set interval. We tend to use small intervals, such as every hour or 10 minutes, from which we can extract image sequences with longer intervals (e.g. one image per day). This camera can be left unattended for a period of time, accumulating images of the glacier. We normally leave our cameras for a summer melt season (May to September) because either the memory card is full or the camera system needs servicing. For more information on the elements of a time-lapse camera system and how it is powered, see here.

Once the camera has been collected, the images can be used to construct image sequences from which observations and photogrammetric measurements can be made. These images can either be selected manually to maintain consistency in illumination or based on time interval. Glacial processes are more apparent when illumination is consistent. This is especially beneficial for looking at longer-term processes such as glacier movement. By constructing a sequence using one image per day with consistent illumination, glacier movement is apparent along with changes in terminus position (see below).

An image sequence constructed from one photo a day at the front of Kronebreen glacier in Svalbard. This sequence spans 15 June to 26 July 2016, covering part of summer melt season. During this phase, the glacier is moving approx. 3 metres per day and calving activity is high. The muddy water in the fjord indicates that meltwater is exiting the glacier, forming a submarine plume that interacts with the saline fjord water.

An image sequence constructed from one photo a day at the front of Kronebreen glacier in Svalbard. This sequence spans 15 June to 26 July 2016, covering part of summer melt season. During this phase, the glacier is moving approx. 3 metres per day and calving activity is high. The muddy water in the fjord indicates that meltwater is exiting the glacier, forming a submarine plume that interacts with the saline fjord water.

Over a summer melt season, marked changes at Kronebreen glacier, Svalbard, are visible. As ice in the upper region flows into the fjord, ice breaks off at the front as if it is being ‘nibbled’ away. This is known as the rate of frontal ablation.  The rate of frontal ablation is higher in the area nearer to the camera due to the presence of a submarine plume, creating a small embayment in the glacier front. The region adjacent to this embayment retreats very little, leaving a preserved pinnacle in the middle of the glacier front. Its retreat rate is likely to be the result of a low frontal ablation rate controlled by a rapid delivery of ice to the region and low calving activity. This region of the glacier front also sits on a topographic high in the sea bed, which has pinned the front in a stable location.

We can examine the processes that contribute to these long-term changes in an image sequence constructed from images at shorter intervals. The sequence below is composed from images of Kronebreen every 10 minutes, covering 4 hours (real-time) in total.

One photo every 10 minutes at Kronebreen (2-6pm 1st September 2016)

An image sequence constructed from one photo every 10 minutes at the front of Kronebreen. This sequence spans 4 hours real-time (2-6pm 1st September 2016), showing conditions at the end of the summer melt season. Here, the circulation in the fjord water can be distinguished based on the movement of icebergs, migration of the submarine melt plume is seen, and calving ice from the glacier front is visible.

Compared to the previous image sequence, we see a different picture here. We no longer visibly see glacier movement or change in the glacier front position. Instead we see shorter-term processes such as migration of the submarine melt plume surface expression. This can be used as an arbitrary measure for the amount of meltwater leaving the glacier. We can also observe icebergs moving in the fjord which can be tracked to indicate patterns of small-scale fjord circulation. This can be especially useful for examining submarine melt, specifically how the fjord water interacts with the front of the glacier.

We can isolated events with even shorter interval image sequences. Over the past year, we have been experimenting with high-frequency time-lapse methods, capturing one image every three seconds for short periods at Kronebreen. Image sequences constructed from one image every three seconds can look similar to video, better showing processes in a high level of detail. This has been especially useful for looking at individual calving events and the study of calving mechanisms.

Large calving event at Kronebreen (September 2015), with ice originating from above and below the waterline. Iceberg approx. 100m wide, 50m high (above waterline only)

An image sequence constructed from one photo every three seconds, showing a large calving event at Kronebreen. This sequence covers two minutes real time at the end of the summer melt season 2015 (00.18 to 00.20).The iceberg that breaks off is approx. 100m wide, 50m high (above waterline only).

Above is an example of a large calving event at Kronebreen at the end of the summer melt season 2015. It is visible to distinguish that this calving event is the result of a complete failure through the ice column, with ice breaking off from above and below the waterline. Initial failure at the top of the ice face causes a rotational break-off of the ice below this, which is likely to have been encouraged by a pre-existing weakness in the ice column such as a small crack or crevasse.

Hopefully with these sequences I have illustrated that different sets of glacial processes work on different timescales. One of the main advantages of time-lapse photography and photogrammetry techniques is that we can adjust the interval rate to look at the process we wish to examine, making it much more flexible than other imagery acquisition. We hope that time-lapse techniques will continue to be used in the study of glacial environments. It is likely that with the ongoing development of camera technology, there will soon be more advantages to using time-lapse photography and photogrammetry.

Advertisements

Inside our cameras

Sometimes we get requests concerning what equipment we use in our time-lapse camera systems. Our systems are not off-the-shelf products, we buy specific parts and put them together ourselves to save money and ensure that the systems contain the most suited components for what we want to do. Here is a summary of the components that make up our systems.

The set-up

One of our cameras overlooking the front of Kronebreen glacier in Svalbard (May 2015)

Me and one of our cameras overlooking the front of Kronebreen glacier in Svalbard (May 2015). Photo credit: Heïdi Sevestre.

1. The camera box

Our camera boxes are custom-made by Alex Hart and the University of Edinburgh GeoSciences workshop. The original box is a Peli iM2075 Storm Case which the workshop team take and modify. The modification involves:

  1. Cutting a porthole in the front of the box for the camera to take pictures from, with two ring plates that hold a piece of fibre optic glass (bought from UQG Optics)
  2. The bottom of the box is mounted with a plate and 5/8″ threaded connector so it can be attached to a surveying tripod
  3. An adjustable shelf is mounted on the inside of the box, on which the camera sits (secured with an M5 bolt)
  4. Two holes are drilled into the side of the box for waterproof connectors to be fitted, which connect to the battery box and the solar panel
  5. An eyebrow is mounted above the porthole, sheltering it from glare and vertical snow/rain

The box allows for easy access to the system, and flexibility on the camera model and lens that is used with the adjustable shelf system.

2. The battery box

The battery box is a customised Peli 1200 Protector Case which contains a 12 V lead acid battery. This powers the camera system and is recharged by the solar panel. We generally do not keep the battery in the same box as the rest of the camera system due to the risk of it leaking and potentially damaging the rest of the system. The box is customised for a waterproof connector to be installed into the side of the box, which connects the battery box to the camera system.

3. The solar panel

The solar panel recharges the battery, keeping the system powered for the duration of the installation. We use 60 Watt crystalline solar panels (bought from Sunshine Solar), which we adapt by reinforcing the cable and adding a waterproof connector plug (see connecting cables for more). It is important to consider what the solar panel is charging when it comes to buying a solar panel.

4. The connecting cables

The connecting cables to the camera box are fitted with waterproof connectors to keep the system water tight. Plastic wrap is also used to protect the cable from the rain, the wind and peckish wildlife – Arctic foxes are notorious for chewing through the cables!

5. The tripod

We use standard surveying tripods to mount our camera box, battery box and solar panel on to. The tripod is anchored  either by burying the legs with surrounding rocks and debris, or bolts which are drilled into the surrounding bedrock. How the tripod is anchored completely depends on the terrain so we often try to bring kit for both eventualities to keep as flexible as possible.


Inside the camera box

Inside one of our camera boxes (April 2014)

Inside one of our camera boxes (April 2014)

1. Canon 600D/700D camera with assorted EF lenses

As well as being a good camera for image quality, we also use the Canon 600D/700D because it is efficient in power consumption, consuming very little power when on and entering a sleep mode between photos. If you are buying a camera for time-lapse uses, make sure the camera can enter a sleep mode (or buy a timer that can be programmed to make the camera sleep e.g. the Harbortronics Digisnap 2100 timer). It is also a good idea to consider the size of the image sensor as this controls the quality of the image. Cameras tend to be pricey when buying them brand new, but you can save money by buying from Ebay. The Canon 600D is no longer made (hence why we have recently started buying the Canon 700D), but there are plenty of refurbished Canon 600D bodies online. Refurbished cameras are new cameras which bear a manufacturer’s defect but have been restored to a fully working state. They are perfectly fine to purchase, just the seller is not allowed to advertise it as ‘new’ (for more information on refurbished cameras click here).

The camera lens also controls the quality of the image, as well as the angle of view. Choosing a specific lens is a trade-off between the field of view and the level of detail. A wide-angle lens (i.e. below 50 mm) is more suited when you want to cover a large area whereas telephoto lenses (i.e. above 50 mm) are ideal for acquiring a high level of detail. This is a good webpage to find out the field of view (given as an angle) which each lens and focal length provides. We use the Canon EF 20 mm, 50 mm and 85 mm fixed focal length lenses depending on exactly what we want to capture. Fixed focal length lens are generally advised over zoom lenses as they are easier to calibrate and introduce less distortion which will be beneficial down the line when extracting measurements from the images.

2. 512/256/128 GB SD memory card

The memory card is what stores the images so it is very important to pick the right one, specifically to pick the right size for what you are using it for. Generally the choice will be between a 512 GB, 256 GB or 128 GB card for longer duration (> 3 months) time-lapse installations. 128 GB cards are very cheap nowadays (roughly £30) and can store approximately 23 000 images (highest quality JPEG images on an 18 MP camera). 256 GB and 512 GB cards are significantly more expensive but may be worth it for high-frequency or long duration time-lapse sequences. These may come down in price when/if the 1 TB memory card is released.

Fun story: Last year we ran into problems with a memory card in one of our cameras at Kronebreen (a Lexar 256 GB card). After taking valuable photos of the calving front over 6 months, the card corrupted and we lost a third of images on the card (9999 images). It was absolutely devastating and meant we had a massive chunk of our data set missing. Both SanDisk and Lexar offer free recovery software when you purchase one of their memory cards. I didn’t have much hope, but on a whim I tried it. The software was extremely slow but after processing for 24 hours… we recovered the missing images.

3. Harbortronics Digisnap 2100 timer

Some cameras have integrated internal timers that can be used to program the image capture frequency. The Canon 600D/700D camera does not though, and generally we want to be able to program multiple image capture frequencies for different times of the day. We use the Harbortronics Digisnap 2100 timer, which can operate in low temperatures to capture images at regular frequencies. The timer consists of four components: the timer itself (3a), the battery converter (3b), the trigger cable (3c), and the connecting cables (3d) between these components and to camera. The timer allows both simple and advanced time-lapse settings, which are programmable via computer connection and an easy interface. The battery converter converts the power source to the voltage needed to power the camera and the timer. The trigger cable is used to connect the timer box to the camera. The connecting cables have to be modified in order to connect to a replacement power adaptor which powers the camera via the battery compartment. This relatively easy to do with a bit of soldering.

4. Silica gel desiccant pack

The packs are handy for minimising condensation as the desiccant balls in each pack absorb and hold water vapour. This reduces the risk of water damage to the system when left out over a long period of time. The packs come as a deal with the Peli cases, but they can also be ordered separately.

Genasun solar controller (not pictured)

The solar controller regulates the power in the system, ensuring that the solar panel recharges the battery and the battery powers the rest of the system. It is not pictured as previously we used to keep the solar controller in the battery box. We changed this in 2015 so the battery boxes could accommodate larger batteries.

Key time-lapse studies into glacier dynamics

Camera sites 8a and 8b at Kronebreen, Svalbard (May 2015)

Two of our stereo time-lapse cameras (cameras 8a and 8b) at Kronebreen glacier (Svalbard), which were installed as part of the CRIOS (Calving Rates and Impact On Sea level) project. These cameras were focused on the front of the calving front to look at surface velocities at the glacier terminus in comparison to calving rate (May 2015)

I have been nearing the end of writing the first chapter of my thesis which is an overview of photogrammetry techniques in glaciology with particular focus of time-lapse photogrammetry. Whilst writing this chapter, I have had to review all previous studies which use time-lapse photography. I found that still a large proportion of studies are developing photogrammetry techniques, and there are only a few studies which actually use the techniques to answer the big questions in glaciology. I thought I would share a list of the key papers that use time-lapse photogrammetry to examine different aspects of glacier dynamics… (if there are studies you think I have missed off this list then please contact me, I’m always looking out for more!)

  1. Dietrich et al. (2007): Examined links between vertical displacement and tidal levels at Jabobshavn Isbræ (Greenland) to determine how much of the glacier tongue was free-floating.
  2. Ahn and Box (2010): Captured daily images of several glaciers in Greenland (Rink Isbræ, Store Gletscher, Umiamako, Jakobshavn Isbræ) to examine links between surface velocity and calving rate. Concluded that velocity speed-ups were caused by large calving events e.g. calving event at Umiamako caused speed-up (17% acceleration) over the subsequent six days.
  3. Kristensen and Benn (2012): Captured daily images during the 2003-05 surge of Skobreen-Paulabreen. Observed intensely crevassed ice at the front and lateral margins during the surge, but little crevassing behind the front. Concluded that the surge was almost entirely driven via basal motion (sliding/deformation), facilitated by trapped pressurised water at the bed.
  4. Danielson and Sharp (2013): Monitored water levels in supraglacial lakes on Belcher Glacier (Canada) using hourly time-lapse images. Linked drainage events in these lakes to four glacier acceleration events (determined using GPS). The time-lapse imagery was also used to determine lake drainage typology, classed by the lake constraints (crevasse or surface topography), connection to the basal hydrology system and the speed of lake drainage.
  5. Rosenau et al. (2013): Determined changes in the grounding line of Jakobshavn Isbræ (Greenland) over time, using vertical displacements (measured from time-lapse images acquired in 2004, 2007 and 2010) as a measure of flexure. They also examined the position of previous pinning points of the glacier front.
  6. James et al. (2014): This was the first study to use a high-frequency time-lapse sequence (one image every 10 secs) to observe a large calving event at Helheim glacier (Greenland) (see time-lapse video here). Vertical displacements at the glacier front showed that the rotation calving event was caused by differences in the fjord bed topography which promoted uplift at the north side of the glacier margin and a depression at the south part of the margin, creating an unbalanced buoyancy equilibrium.

From all of this, I have found that the future of terrestrial time-lapse photogrammetry is trending towards its valuable ability to examine different aspects of the glacier system simultaneously – glacier velocity, fjord dynamics, surface lake drainage, calving dynamics… and others. These can be studied using different image capture frequencies and over different lengths of time, and I think we will begin to see much more high-frequency time-lapse sequences based on the useful information gained from them so far.

Fieldwork & Film


The Fieldwork
Last year, we placed seven time-lapse cameras at the margins of Kronebreen from May to September 2014, capturing images every 30 minutes. These were intended to collect high-resolution surface velocities, calving rates and surface lake size that would complement findings from a continuous record of bed water pressure.

Five out of seven of the time-lapse cameras worked. Cameras 4 and 7 were recycled from a previous installation, but only worked for a week due to a power shortage. Unlike the Canon 600D camera, the Nikon D200 camera cannot enter a sleep mode and consumes more power on standby and during image capture. The five Canon 600D cameras successfully captured images throughout the season, except one which fell over two weeks before they were collected. It is suspected that one of the drilled bolts stabilising the tripod popped because of freeze-thaw expansion.

The positions of the time-lapse cameras in 2014 (top) and 2015 (bottom). Map source: Norsk Polarinstitutt (toposvalbard)

The positions of the time-lapse cameras in 2014 (top) and 2015 (bottom). Map source: Norsk Polarinstitutt (toposvalbard)

The images were used to obtain surface velocities and calving rates using a series of photogrammetric techniques – feature tracking, image registration, and image transformation. We underestimated the value of the data from these cameras though. The quality of the data far surpassed our intention to use as a complimentary aid to the bed water pressure record. The higher resolution gives greater insight into short-term velocity changes, and could be used to examine calving behaviours. Therefore we decided to re-deploy the time-lapse cameras to capture images over summer 2015.

In May 2015, 8 cameras were installed at Kronebreen. Four of these consisted of new sites that required location scouting and tripod installation, whilst the other four re-occupied sites from the previous year. These were positioned at the glacier margins as pairs to enable stereoscopic photogrammetry. Stereoscopic photogrammetry is the extraction of meaningful data from two sets of images focused on the same target. Unlike monoscopic photogrammetry (analysis using one camera), common features in two image sets can be triangulated to create a three-dimensional representation of the surface (i.e. a Digital Elevation Model – DEM). This is a reliable way to gain absolute measurements as it is more accurate in the translation from pixel to real-world distances.

It took three days to deploy all the cameras, with the help of a helicopter (and pilots) to ferry us around the mountains adjacent to Kronebreen. We shared helicopter time with Jack Kohler (Norsk Polarinstitutt), Katrin Lindbäck (Uppsala), Ankit Pramanik (Norsk Polarinstitutt) and others, who were GPR surveying a number of glacier in the Kongsfjorden area. Therefore we had to coordinate helicopter drop-offs, and make sure we were ready and organised for pick-ups. Our helicopter pilots Jon Arve Ramstad and Gunnar Nordahl were very flexible and also really curious about the work we were doing, often helping out with carrying equipment (and teaching us swear words in Norwegian… essential stuff).

Day 1
The team of four (Nick Hulton, Heidi Sevestre, Doug Benn and myself) were first dropped off at camera sites 8a and 8b, with the intention being to split into two groups to work simultaneously on each camera. We managed to find a site with prime viewing over the glacier front where both cameras could be installed, roughly 10 metres apart. Nick and Doug primarily worked on camera 8a, which is paired with camera 1, focusing on the calving front. Heidi and I worked on camera 8b, which is paired with camera 4a (up glacier). The ground was very dusty, with a loose surface roughly 3 inches thick. Beneath this was hard impenetrable permafrost, so it was very difficult to either bury or bolt the tripods. Nick had pre-empted this, and had the idea of using buried anchor plates to stabilise the tripods – guide wire attached to the tripods is threaded through metal plates which are buried in the ground. All went smoothly bar the loss of Nick’s bag (and his down jacket which held sentimental value having been with him on a trek across Greenland), which went tumbling downhill into the glacier as he was collecting large rocks to anchor the tripods.

May 2015: Camera sites 8a and 8b (photo credit: Nick Hulton)

May 2015: Camera sites 8a and 8b (photo credit: Nick Hulton)

The group split up from here, with Heidi and Doug dropped at camera site 1 to dismantle the tripod we left there last September, whilst Nick and I went to camera site 2 to install one of our camera boxes on an existing tripod. These two tripods have been here much longer than the others (since 2012 approx.), so are heavily frozen into the ground. Heidi and Doug resourcefully used hot water from their thermos flasks to melt the surrounding ground, so they could extract the tripod from camera site 1.

It was here that we could really observe the changes at the calving front. Over the winter, the calving rate has reduced, causing the front to stretch forward. Velocities tend to be low so little ice is replaced from up glacier, hence the ice near the front simply advances by stretching and thinning. We hope that the cameras will capture changes at the front over the summer, when the calving rate front is much higher and the ice cliff will steepen as the glacier retreats back to thicker ice. Our day ended after we placed another of our camera boxes on a tripod at camera site 3, which was installed in May 2014.

Day 2
On the second day, Heidi and Doug collected a GPS box from the glacier surface and recovered a tripod from camera site 6. The GPS had been logging its location since September 2014, and can be used to measure the glacier surface velocity. This can be compared to the surface velocities derived from the time-lapse images as a measure of confidence. Meanwhile, Nick and I were in the research station putting the final touches to the remaining time-lapse camera boxes – programming the camera timers, configuring the electronics, calibrating the cameras, mounting the solar panels on to the tripods etc. etc. This preparation is crucial to our field installations running smoothly.

Day 3
On the third day, Doug and I were dropped off on Garwoodtoppen (the mountain to the south of Kronebreen) to install cameras at sites 5 and 9, whilst Nick and Heidi were on Collethøgda installing cameras at sites 4a and 4b. The installations on Garwoodtoppen largely consisted of digging. Lots of digging. The permafrost is much softer on Garwoodtoppen, meaning the tripod legs can be dug in and there is less need for guide wire anchoring. We had four hours to install the two cameras with one (blunt) ice axe between us and a half hour walk between camera sites. I originally invested in some DMM Fly ice axes to encourage me to get out in the Cairngorms, but I am ashamed to say that they have seen much more digging action than climbing. Timing was tight, but we managed to install everything before the helicopter picked us up.

Nick and Heidi were dropped at camera site 4a, where we installed a tripod last year. From here, they scouted out the location for camera 4b. It was initially thought that camera 4b could be installed within close proximity to camera 4a, but there was little good ground and the glacier was hidden from view by the mountainside. They eventually found a suitable site 1 km away that was right on the edge of the mountain top, consisting of little permafrost and exposed gypsum bedrock. Here, they drilled expansion bolts into the bedrock to stabilise the tripod, and gained a terrific view of the mid-section of the glacier tongue.

May 2015: Heidi and Nick at camera site 4b (Photo credit: Nick Hulton)

May 2015: Heidi Sevestre and Nick Hulton at camera site 4b (Photo credit: Nick Hulton)

With the eight cameras installed and the team finished within the allotted time, the helicopter pick-up went smoothly and we returned to Ny Ålesund…

…until worry set in that the cameras were programmed wrong or the tripods were not well anchored or the GPS locations were not exact etc. etc. Luckily a window opened up the next day when the weather was calm and the helicopter was free, so we re-visited camera sites 4a, 4b, 5 and 9. We worked from 8pm till midnight taking accurate GPS locations, better anchoring the tripods, checking the cameras were working, and downloading the first 24 hours of data. Thankfully everything was working, which gave us some reassurance that the cameras would survive the summer.

In September 2015, myself and UNIS post-doc researcher Sarah Thompson will be returning to Kronebreen to collect the cameras in.

The Film
We started filming our fieldwork in May 2014 when Silje (Smith-Johnsen, UNIS masters student), Heidi and I thought it would be fun to take GoPro cameras to Ny Ålesund. We filmed the first deployment of the time-lapse cameras at Kronebreen, which successfully captured images of the glacier from May to September 2014. After the fieldwork had finished though, we found ourselves with lots of raw footage that we knew we would rarely look at again in its current state. Therefore we decided to compile all the footage in one place where it could be edited into a short film consisting of footage highlights. I had all the equipment and software to do so, as I had originally wanted to study art, film and animation at university.

The result was a four minute film that summed up the focus and mood of the fieldwork – intense, challenging, and fun. At this stage, I showed the film to Nick who was really enthusiastic about it and contributed some great close-up footage of Kronebreen’s calving front. The film was then passed on to the UNIS webmaster, who uploaded it to the UNIS Youtube page and has clocked up over 1000 views and been used for outreach purposes on numerous occasions. Along with the follow-up fieldwork film of the camera retrieval and the video of the time-lapse image sequences, the films have been featured on NRK and ITV News. The response was overwhelming. I was completely surprised by the enthusiasm displayed by all I showed the films to. I love making them, and it is such a bonus that they have been well received.

As this trip came around, we decided to take the cameras again to film the fieldwork. Nick joined the GoPro crew, with a chesty harness along with Heidi, and I decided to go with a head strap to get better POV shots. Nick also shot footage with his Panasonic Lumix GX1 camera, which proved really useful for steady landscape shots that I could stabilise in the editing stage to produce smooth, detailed footage. Both Nick and I also had automated time-lapse settings on our cameras, which proved really useful for producing time-lapses of our installations. It was difficult to film at times as the cold temperatures would often diminish our battery life, but overall, we shot roughly 12 hours of footage.

Over the course of three fieldwork films, I’ve come up with a couple of my own personal do’s and don’ts when it comes to filming, editing and producing:

1. Always remember that the fieldwork and the research is the highest priority
The work will always come first. This is why we use GoPro cameras, as they are hands free and easy to operate. Once recording, you can just forget about them and focus on the fieldwork. Also, I try not to let film editing and producing eat into my PhD work time – I am completely guilty of this sometimes (e.g. I am currently writing this in my office in the middle of a weekday with work deadlines looming and future fieldwork creeping up fast), but I am trying to get better!

May 2015: myself, Jon Arve Ramstad, Gunnar Nordahl, Doug Benn and Nick Hulton at camera site 3 (photo credit: Heidi Sevestre)

May 2015: myself, Jon Arve Ramstad, Gunnar Nordahl, Doug Benn and Nick Hulton at camera site 3 (photo credit: Heidi Sevestre)

2. Welcome people who want to be involved
Give them a camera, ask them to get specific footage, show them a rough cut and ask for advice, anything! I always need that extra bit of footage or feedback. And I make an effort to acknowledge everyone who helps out. So many people are involved in our fieldwork films and their roles often crossover, so I have tended not to specifically assign people’s roles in the credits.

3. You don’t need expensive equipment to make a good film
Although good image and sound quality can enhance a film, it is the content that ultimately dictates how good the film is. Only invest in good equipment if it will improve the content. The previous films largely consisted of footage highlights set to music with the odd bit of text for context. I wanted to make this film much more informative, so decided a voiceover would be the best way to present more information without detracting from the film content. Reluctantly, I did the voiceover myself as I didn’t have the time to coordinate others to do it (that pesky thing called a PhD kept getting in the way). After brief trials with in-built camera and laptop microphones, I found that their sound levels were inconsistent and promoted a muffled tone (it was also very eye-opening for me as it demonstrated to me how much I mumble). The quality detracted from the message of the film, so I bit the bullet and bought an external microphone (a RØDE VideoMic Pro microphone), which really improved the clarity and tone of my voice. This is an example of investing in equipment to improve the content.

4. Securely store all your footage
As we have to be really careful storing all our time-lapse images, we have a lot of external hard drive back-ups (I think we currently have the images stored in 5 separate places, with 24TB of allocated external hard drive space in total). I also keep all the footage from each field season, which was particularly useful for this film as I could use old footage to compare the state of the glacier through time. Finding matching footage from the helicopter was incredibly lucky, and the time-lapse sequences are an obvious way to show the differences in the calving front between summer and winter.

5. Be brutal with editing…
Sometimes a piece of amazing footage has to be cut because it doesn’t fit in with the rest of the film, and often it can be hard to let go. For this film, we got some awesome footage of the calving front from sea level as PhD student Kristin Schild kindly offered me a boat trip in exchange for help with her fieldwork. In the end I had to cut it though as it didn’t blend well with the helicopter shots and it would have detracted from the overall message of the film.

6. …And also be patient
Film rendering has become the bane of my life. The dynamic maps and diagrams that appear at the beginning of the film took roughly 12 hours to animate, largely due to the rendering time (i.e. the transformation from a collection of edited film clips to a final continuous sequence). I think it has really paid off though, and I will be looking at transferring these animations to conference talks and presentations, so that painful 12 hours is not completely in vain.

7. Keep it short and sweet
I have a general rule to keep the films to less than 6 minutes, although I often don’t strictly keep to this. This is to keep it concise, and limit it dragging. I’d be really annoyed at myself if I managed to make glaciology somehow boring.

8. Use license-free music
Using copyright music limits the ability to share the video, and often ends it being taken down from Youtube because of copyright infringement. Hence, I usually dig around for license-free music. Often I explore small artists who offer free music downloads on sites like Soundcloud, or browse license-free music sites such as Incompetech, Bensound, and Mobygratis.

May 2015: Camera 5 looking over Kronebreen

May 2015: Camera 5 looking over Kronebreen

9. Consider who might watch the film
If you are aiming to use the film for outreach, the audience could be anyone from school children to academics. Although I personally don’t have a problem with swearing on camera, others might have a sensitive disposition to it. In the camera retrieval fieldwork film from September 2014, I kept in some swearing but bleeped it. In hindsight, I realise I should probably have just edited it out because it could limit the viewing audience. This time round, I made two versions. The uncensored version is a lot more comical, and in some ways also more real. The censored version is a safety net to make the film accessible to all. Better safe than sorry.

10. Always keep in mind the aim of the film
The aim of the previous films were to show others what we get up to on fieldwork, hence there was much more focus on presenting the footage in a chronological order that told a story. The aim of this film was to be much more informative and not merely repeat the previous formulae. I mixed up the ordering of the footage, with the voiceover dictating the structure of the film. It felt necessary to put the dynamic diagrams at the beginning of the film to give context to what we were doing and why we were doing it.

These are just my personal guidelines and I’m sure they will change over time. Next I’ll be looking to pack more information and technical glaciology knowledge into the films, whilst also keeping them entertaining. There is some pretty exciting fieldwork coming up at Tunabreen, as well as the camera retrieval from Kronebreen, which will be challenging and keep me busy for a fair while after. Watch this space (you may be watching for a while… just to give you some warning).