Volcano Photography - Beginners Guide

Introduction

The following sections are intended to provide guidance for anyone who would like to try volcano night photography themselves. I will try and cover the most important aspects in seperate sections dealing with photographic equipment, basic techniques and safety issues. Some illustrations have been included to show the effect of different techniques.

Photographic Equipment

Cameras - Digital or Analog ?

Light measurement during night photography of active volcanoes is critically important, especially as the subject may be emitting significant amounts of light itself. If exposure times are long, exposure bracketting may not be practical. Hence, digital cameras have a major advantage in that a test shot can be made and the exposure settings changed rapidly after viewing the result. Further, in environments where there may be a lot of ash flying around, opening an analog camera body to change film is not very practical. Ash will cause major scratching if it gets inside. When I use analog bodies, I try not to change film in the field and additionally seal the bodies with tape to reduce ash influx.

The major weakness of many digital cameras is low dynamic range i.e. it is easy the burn out the highlights before the darker areas have been adequately exposed. However, although film generally has a higher dynamic range, if it is digitized, the dynamic range of most scanners will remove any advantage one initially had. Further, digital SLRs are expensive compared to the maybe 30 Euros you would have to lay out for a simple, but perfectly adequate, analog body (e.g. Canon EOS 500N) on ebay.

It is important, whatever camera you use, to take enough batteries along. Long exposures significantly drain camera batteries.

Lenses

If you are dealing with intensely glowing material, basically any optically reasonable lense will do. Some remaining light is often useful in this case so landscape details can be captured without burning out the lava. The optical length of the lenses required will depend on distance to the volcano and photographic preferences (landscape v detail).

For photography of weakly glowing material or photography at night where one intends to capture landscape detail (a bit of glow on a black background is not much use) it is useful to carry lenses with a wide maximum aperture, otherwise each exposure may need to be very long, which is obviously inpractical.

On a moonlit night, a lense set on aperture f2.0 can capture sufficient landscape details to put an eruption into context with under a minute exposure at iso100. If you havent got a wide maximum aperture lense, you may concentrate more on taking photos at dusk and dawn when there is more available light, but it is sufficiently dark to clearly see incandescence. This also can give a nice blue coloured sky, however, since light conditions are rapidly changing at these times, judging exposure lengths can be slightly complicated.

Using a wide aperture also allows one to freeze the stars on a clear night. Smaller apertures require longer exposure times which will result in stars being depicted as lines, due to their movement.

Obviously, the optical length of the lenses required depends on the subject. If you only want to carry one wide-aperture lense, you can´t go completely wrong with a 50mm lense. Wide apertured 50mm lenses (e.g. Canon 50mm f1.8) are relatively cheap. Image quality of 50mm lenses is usually not bad, although as with all lenses used wide open, images will tend to be somewhat soft. Focusing may be difficult at night and is especially critical when working with wide apertures. When there is a full moon, autofocus will normally be able to lock onto it, if infinity focus is required. Otherwise, it is useful to test the lense beforehand and make markings indicating where the best focus point for a certain distance is (note: this may also vary with temperature). The indications provided on the lense are nowhere near accurate enough. Once you have got correct focus, disable autofocus.

Usually, you dont know beforehand exactly how close you will be and what the best composition could be. Since, long lenses with wide maximum apertures are heavy, the choice is often difficult. Usually a compromise has to be made between weight, lense variety and optical quality. It is also very important to remember that lenses, just like camera bodies, do not like volcanic ash. Many of my lenses make scraping noises when i turn the focus ring due to trapped ash. You cannot protect them all of the time if you want to use them but the should be well wrapped up when not in use (i roll them up in plastic shopping bags), and covered as much as possible with e.g. a cloth when ash is falling. Moisture is also often a major problem.

Tripods

If you are on top of a volcano, there is a fair chance that it will be windy. A sturdy tripod is essential and should be only extended as far as absolutely necessary. If the landscape is free of vegetation you will usually not need a long tripod at all. To save weight, I often remove the bottom leg sections from my tripods and put plastic caps over the exposed bottoms of the middle sections. The center column is best left at home if you can seperate it from the tripod mount. Cameras mounted on extended center columns are very unstable. Carbon tripods are preferred for weight reasons, but are more expensive and get very easily scratched when ash enters the joints. Obviously, to avoid camera shake during shutter release a cable-release is needed. A cable extension is sometimes useful so one can sit comfortably, further away from the camera once it is set up.

Basic Techniques

Night Photography

Different types of volcanoes require different approaches. Incandescence (glowing) of fresh lava, such as in lava flows or ejected during strombolian eruptions (where glowing material is thrown out of the crater in often high trajectories) can even be recognized during daylight. Lava domes on the other hand, or the chemically unusual low melting point lava found at Oldoinyo Lengai volcano do not generally glow visibly in daylight conditions and usually require a much longer exposure time. Sometimes, long exposures will reveal incandescence not visible at all to the naked eye.

Lava Flows without significant crusting are generally best captured in the evening or early morning when there is sufficient residual light to capture landscape details without completely burning out the flow (or even worse the gas cloud usually found above it). The appearance of the flow can be varied by changing exposure times. Short exposures with wide apertures will obviously freeze any surface structure of the flow, whereas long exposures with shut down apertures will often give the flow a stripy touch. Intense continuous lava fountains can be treated similarly.

Short Exposure of Lava Flow at Etna Volcano, showing surface structure of flow. Taken in the evening (1/60sec f5.6 iso100)	Tripod mounted exposure of same flow at Etna Volcano. Taken in evening (2sec f5.6 iso100). Note that flow is burnt out with no visible surface structure, but angle of shot reduces size of burnt out area and exposure length makes context of flow visible.

Strombolian eruptions are probably the most widely photographed eruption types. In strombolian eruptions, strongly glowing material is ejected explosively from the volcanic crater and flies in a more or less parabolic path before reaching the ground again. Although the material is strongly glowing, burn-out is not such a major problem, since the volcanic bombs only are in each part of the picture for a fraction of a second. Incandescence is nevertheless sufficient to trace the path of the trajectory during the photographic exposure. The paths of the trajectories can usually even be seen at f8, iso100. It is important to capture the beginning of the eruption, since trajectory paths should not start in mid air. Hence, it is advisable to start the exposure and hope that an eruption will occur during the exposure period. This can take one through a lot of film without an eruption but when it works the best results are achieved.

What a small strombolian eruption looks like in daylight. The nighttime trajectory images can mislead some non-photographers into thinking that a continuous fountain is being shown. Each parabola is however simply traced by a single glowing lava fragment.	Multiple Strombolian Eruptions captured at night by long exposure technique. Note slight burnout in spite of f8 aperture. Exposure length was about 15min, during which the eruptions occured.

Obviously, digital cameras have a major advantage here as you can basically set them up and leave them running taking series of pictures all night if you have a timer device. On Stromboli volcano (the volcano giving this type of activity its name), the vents glow between eruptions. If there is no wind, volcanic gases collect above the vents and are lit up by vent incandescence. This results in bright red areas with no structure above the vents during long exposures. In this case, one needs more light or a change in conditions to capture the best shots. Another problem is that at the bottom of the eruption "column" the material often has not spread out very much. Consequently, in this area burn-out problems can still be an issue, even at f8, iso100.

If an eruption involves a lot of ash, this may obscure the incandescent material and significantly inhibit night photography.

Strombolian Eruption where the shutter was released after the eruption had started. Note that the trajectories do not start at their source. This should be avoided.	Stombolian Eruption obscured by volcanic gases hanging around the vent in low wind conditions. Note that landscape cannot be exposed enough as picture already overexposed in center long before any landscape structure could be captured.

Volcanic Domes are also interesting yet less popular photo motifs. Depending on the structure of the dome and extrusion rate of lava , incandescence may be hardly visible. Occasionally, incandescent material can break off Domes and roll down the flank of the volcano. This can be captured much as a strombolian eruption, with the paths taken by incandescent rocks rolling down the volcano are made visible by the long exposure. Incandescence is however likely to be less strong than in a strombolian eruption. Even when no rockfalls are taking place, an active lava dome glows from cracks and at points of particularly high lava extrusion. Long exposures capturing the dome structure together with the glowing areas can give highly satisfying results. Longer lenses are advisable for lava dome photography , since approaching an active lava dome is generally not advisable.

Lava Dome of Soufriere Hills Volcano, Montserrat, during daylight	Several minute nighttime exposure of the same dome (from a different angle) using a 400mm f5.6 lense with wide open aperture. Dome incandescence and small rockfalls are visible.

Oldoinyo Lengai volcano. Lava temperature at Oldoinyo Lengai volcano is unusually low, resulting in weak incandescence not visible during daylight. As a rule of thumb, an active lava flow on Oldoinyo Lengai can be exposed for 30secs at f2.0 to give it a strong red colour. This time is also a suitable minimum exposure time for the surrounding crater landscape in full moon conditions.

Daytime view of a lava flow at Oldoinyo Lengai Volcano (Note: no visible incandescence)	Nighttime view of lava flow at Oldoinyo Lengai Volcano. Taken with Canon 50mm 1.8 lense (40sec, f2.0, iso100 film). Note: stars appear as dots, not lines, due to short exposure.

Daytime Photography

Ash Clouds / Pyroclastic Flows. Nighttime photography of pyroclastic flows emanating from Domes is not really possible. The same applies to ash clouds. These are best captured during the daytime. As with all other volcanic phenomena captured during the day, general rules of photography apply which I will not go into here. One or two minor points should be mentioned though. The autofocus of most cameras has difficulty focussing on ash clouds in certain light conditions, since they often lack any high contrast structures. If this problem occurs, it is advisable to focus on a more contrasty object equidistant to the motif (e.g. the edge of the crater against the sky) and then once correct autofocus is confirmed, deactivate the autofocus. Further, if you want to freeze motion (e.g. lava bombs in flight), a short exposure time is necessary (e.g. 1/1000 sec), just as with photography of flying birds. Longer exposures can give a more dynamic but less sharp touch. Simply a matter of taste.

Ash cloud at Mount Etna, 2006	Unusually ash-rich eruption at Stromboli volcano in 2006. Note that the exposure time was 1/1000 sec, sufficient to freeze the motion of the lava bombs.

Safety Issues

Clearly, volcanoes are potentially dangerous. You should be aware of volcanic hazards and make sure you get reliable local advice before approaching a volcano. Please do not ignore warnings and unnecessarily put yourself in danger. If necessary, just use a longer lense. I am not a trained volcanologist, so please dont ask me how close you should go.

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