OUCC Proceedings 13 (1991)

Spanish Exploration

Proc. 13 Contents.

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Cave of the Witch's Eye

Graham Naylor

The making of the video.

Following the publication of Dave and Richard's book Beneath the Mountains, Richard became keen on the idea of making a film of Oxford's exploration of caves in the Picos. Having had no experience of filming anything, let alone underground, it was easy to become infected with Richard's enthusiasm. As with all of Richard's ideas it was going to be a bit of an adventure - the undertaking turning out to be somewhat more arduous than his original alluring description suggested! So it all started with avid descriptions of film formats, friends who could do the editing, ccd chips, how the new technology of sensitive video cameras would make it all so easy, fame, fortune, etc., etc.

The initial underground filming attempts using a Radio-Rentals video camera indicated acutely the practicalities and difficulties associated with taking pictures in caves. For lighting I bought a 100W quartz halogen search light from Colemans with the beam de-soldered and re-adjusted in its mount to produce a divergent bulb instead of a parallel one. I also purchased some gas lights and used aluminium foil to try and direct the light - these proved to be quite useless. Having never been down Sunset Hole before I didn't realise how wet it was and so unsuitable for filming. We were able to get about 10 seconds of video recorded before the camera view-finder stubbornly flashed "Dew" and refused to operate any more. A prolonged stop in the Hill Inn was required to dry out the camera.

After several weeks the memory of this initial failure faded and I made the fatal mistake of flipping through camcorder magazines looking at the various models for sale. For underground use a camcorder had to be both compact and sensitive enough to operate under quite low light conditions. VHS-C and Video 8 are compact tape formats and so were the logical choice, with Video 8 offering superior picture quality. A new camcorder from Panasonic using a new format VHS-C claimed to have better resolution still, and Sony had a splash-proof camcorder, the SP5, using Video 8 tapes. I went into a local shop to test these two cameras using a cardboard box with a photo stuck inside it to act as a model cave with low lighting conditions. Pointing the camera through a hole in the side, the SP5 gave better pictures than the Panasonic under the lowest lighting. Given its greater sensitivity and tolerance to water I purchased the Sony.

More underground tests were performed using this camera down Swildon's and Nettle Pot, with somewhat more success than previously due to the water tolerance of this camera. I was able to carry it around in the cave using a large (and consequently troublesome) ammo can. For lighting I initially experimented with a home-made carbide light using twelve jets to get a lot of light and an umbrella sprayed with silver paint to direct the light up Elizabeth shaft. This proved to be quite ineffective, and besides a big boulder landed on it. The best solution proved to be quartz halogen lights powered by 12V sealed lead-acid batteries. The batteries (from Farnell and Maplin electronics) were fitted into ammo cans with cut-up pieces of Karrimat as padding. Connections to the lights were made using car cigarette lighter sockets mounted inside the ammo cans to keep them dry during transport.

The quartz halogen lights used in addition to the Colemans search light were two car fog lamps (55W each) and two utility lights from Halfords (55W each). Normally only one to three lights were used at once, but some redundancy of equipment used underground was necessary due to multiple equipment failure. These lights did however give non-uniform lighting due to the moulded lenses and caustics produced from the reflectors. This was overcome by sticking frosted gels to the front of the lights to spread the light out. These lights proved to be adequate in most passages and small pitches but wholly inadequate for large chambers such as Just Awesome and large passages such as the London Underground.

The camera was powered by small Ni-cad batteries of which I had two, each lasting about 30 minutes. When using a camcorder you can, with 30 minutes of camera life, expect to record no more than 15 minutes of video. It was necessary then to be able to recharge the batteries underground. I built a small charger using a pair of 4.5V flat pack batteries in series, a resistor to limit the current and a simple timer circuit and relay to disconnect the current after a pre-set period (about an hour). One battery was always charging while the other was in use.

I found The Video Maker's Handbook by Roland Lewis was very useful for details of how to use the camcorder.

In Spain the first filming was on the surface at the camps and on the walks up the hill to Top Camp and the cave entrance. It was later when we came to edit the shots in the studio that the lack of a prepared storyboard before the filming showed itself as a serious deficiency.

The underground shots were taken on two trips, the first a one-day trip to film and carry the equipment as far as Pessimist's Pot. The style of filming was to try and give the feel and impression of a real caving trip rather than show highly illuminated passage. Filming in Paradise Rift gave some shots which though they had little technical merit did give a dramatic impression.

The filming of the next section, from Pessimist's Pot to the underground camp, was done on a camping trip. On the trip down to the camp the equipment was picked up at Pessimist's Pot and the first job was to film down the shaft. From the top it was easy to shoot Harry abseiling down carrying a light while Sherry shone her light up. Given the size of the shaft, illumination was very poor, but at least gave the impression of descending into complete blackness! I then tried filming on the way down. I hung from Harry on a cowstail, and he operated the descender while I pointed the camera and the light. The shots turned out to be useless as we spun round the rope faster and faster as we approached the bottom. By the time I got down I was dizzy and completely gripped.

Filming continued down the main shaft with notable communication diffficulties on the numerous rebelays. The whole process was made all the more difficult by the tackle bags of camping gear we had to carry in addition to the filming equipment. At Just Awesome we met the photographic team, so we left the filming gear and returned with them to the underground camp.

The following day Sherry and I filmed down the streamway. Carrying all the filming equipment down the streamway between just two people was quite difficult, though at least the passage was substantially flat and without squeezes or rifts. Meanwhile Wlodek and Harry went to climb up to a passage that Wlodek had picked out with the quartz halogen lights high up on the side of Just Awesome. Wlodek, who is crazy, climbed 40m up a smooth, overhanging flowstone cascade with very limited protection to find a massive, dry, bouldery passage some 70m wide. Not only did this add substantially to the length of the explored cave, it turned out to avoid the streamway and provide a very handy short cut to camp. It was immediately christened the London Underground.

That evening at camp the remainder of the video tape was used to film the jovial and not so musical activities around the camp stove. The next day we surveyed the London Underground, and the following day the filming equipment was taken out again. Carrying ammo cans of lead acid batteries and a large ammo can with the camcorder up 800m of pitches and through the various rifts can only be described as extremely arduous. I must thank Sherry, Harry and Wlodek very much for all the help required on this undertaking.

Back in the UK Richard had lined up Alan Lacey to help us edit the video using the studio at Moorfields Eye Hospital. It was a long job converting the rough shots we got in Spain, some slides taken by Martin Hicks and graphics of the cave survey into what in the end made quite an interesting video. Now that my memories of all the carrying and hard work are beginning to fade, I think the end product was worth all the effort!