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Equipment for Cave Photography

This article, by ALAN COASE, is from a paper delivered by him to the C.R.G. We are particularly pleased to be allowed to reprint this in the B.B., since it follows the tradition set by his brother Don on cave photography.

Portability, reliability, versatility.  The cave photographer may argue at length about his specific requirements in equipment, but undoubtedly these qualities would be amongst the most important he would assess.  Clearly the object of is photography, his financial resources and the nature of the caves with which he is most concerned also playa major part.

The writer has increasingly found that his cave photography ends to divide into two distinct forms. On the one hand there are the comparatively casual photographs taken during the course of other caving activities whilst on the other there are those obtained as a direct result of an essentially photographic trip.  In discussing the range of equipment available for such diverse ends, it is hoped that the range of equipment reviewed may assist others in their selection.

As specialised fields (for example, close-up techniques) are being discussed by other speakers, little or no emphasis will be placed upon equipment solely relevant to them.  The paper will be principally concerned with the carriage and protection of equipment; cameras and lenses; camera supports; flash equipment; films, and miscellaneous aids.

Transport And Protection

The essential requirements for carrying equipment underground are that the cases should be reasonably lightweight and portable, strong and completely waterproof. Fortunately, various military authorities have had similar needs and in the form of surplus ammunition boxes, a nearly ideal case is available at a relatively low cost.  Such boxes come in two sizes and have a very simple and efficient rubber seal.

The two sizes fit well with the two categories of photo¬graphy outlined above; for the smaller one is easy to carry and will comfortably accept a small amount of first aid kit, food and lighting spares as well as a small camera and flashgun.  The larger case is sufficient for a more complex outfit including perhaps a single lens reflex, an alternative lens, one or more flashguns and bulbs and even a compact folding tripod.  The boxes can be lined with foam rubber or neoprene to cushion the equipment, or even full customised so that every item has its specific place.  The inside of the lid can also be utilised for a few technical details. viz.  Guide numbers for a particular flash/film combination.

Although other cases do exist on the market, few of them seem very suitable. One that does merit attention however is the Rollei Matal ever ready case.  This extremely ingenious, comparatively lightweight case has been design with fairly tough treatment in mind and, used in conjunction with an ammunition box for extreme conditions, might prove very effective. However, its new price is very high.

A number of underwater cases do exist for some popular cameras, but generally cost and bulk rule these out.  A number of do-it-yourself ideas for plastic underwater cases have been outlined recently in photographic and sub aqua journals.   These have primarily been designed for underwater work, but they could equally well be used for our purpose if flash synchronisation is maintained.

An easier and quite useful aid is the construction of a neoprene "wet suit" cum ever ready case for the camera.  The object is not; of course, complete waterproofing, but to provide a shock proof layer and to minimise damage from muddy hands.  The one-piece case is tailored to fit as tightly as possible with apertures left wherever necessary for viewfinder, speed dial etc.  A further modification is to fit the lens barrel focussing ring with a neoprene skin on which the focussing distances are clearly marked in paint.

Camera Supports

The main form of support is, of course, the tripod which is really essential for the more complex aspects of underground photography.  The chief problem is of reconciling the need for absolute rigidity with portability. Generally speaking the really compact tripods with brass spring catches and folding tubular legs are neither very stable nor very enduring.  At the other extreme the really rigid studio tripod is far too cumbersome for all but the easiest caves.  Fortunately it large number of tripods do lie between these extremes.  Some of them are nearly ideal for our purposes. Simplicity of construction is a major virtue especially in the locking mechanism on the legs. Some rely on a twist lock mechanism based on nylon threads, but cave grit soon reduces these to impotence.  Far better are the clamp or wheel locking devises which arc usually employed on U-section legs which are easily accessible for maintenance or cleaning. The Linhof range particularly fits the bill here and their Lightweight Professional is ideal for serious cave photography; being stable, tough and yet relatively light in weight.  Its stability is increased by the umbrella strut construction linking the legs to the centre column.  While expensive at list price, Linhofs do appear to be relatively common second hand.

Compact and ingenious camera clamps are readily available but the principal disadvantage with these is that one cannot always find suitable clamping positions in a cave.

Pistol grips and/or flash brackets have considerable virtues where they permit the flash to be used away from the camera and a built-in cable release further reduces the handling of the camera.  However, they seem best suited to 'trip' photography which by their very bulk they may complicate.

Flash Equipment

Discussion is effectively limited to the question of bulb and electronic equipment, there being no reference to flashpowder, magnesium ribbon or other lighting forms, although it is of course possible to obtain cave photographs by using candles, carbide lamps, portable gas lamps etc. as light sources.

The relative values of bulbs and electronic flash equipment are frequently discussed in the photographic press.  Often it is economics that determine the answer reached but in cave photography, where lighting techniques are of major importance, other factors such as light output, size, weight and safety also require consideration.

In terms of light output, flash outfits are generally far more powerful than electronic units.  To approach the same power output the latter are at present very large and bulky but time is an important factor here for, while miniaturisation is occurring with both groups, the greatest potential lies with the electronic units, which are far smaller than the corresponding units of a few years ago.

An increasing degree of 'automation' is also being developed in electronic units where 'sensors' are beginning to take some of the guesswork out of guide numbers.  Similar units are readily available in the form of 'slave guns' which instantaneously trigger off second bulb or electronic guns.  An ingenious bulb unit incorporating such a device is the "Bo-Flash", marketed by Bowens Ltd., at about ten guineas. The gun allows bulbs up to PF 100 in size to be fixed independently of an operator and may be attached to a second tripod or suitable rock by built-in clamp.

An equally interesting electronic unit is the German Unmat 6000 which, at about £30, combines the function of a normal electronic unit with a reasonable output, with that of a slave unit which can be fired off from another flashgun without connecting cords etc.

The economic factor is rather brought to the fore by these two guns, for the bulb unit costs only about one third of the electronic and, even with the smallest bulbs available is more powerful.  However, when running costs are considered the equation takes on a different form. The cheapest flash bulbs are about 4p each and of course can only be used once, whereas the electronic flash merely requires charging and maintenance, which with a reliable make should be minimal.  (For example, my Metz 163 has had fairly full use for over three years and has needed no replacement parts.   This may be in part attributable to the neoprene 'wet suit' in which it too is closeted for its underground visits.)  Thus, if only a few flash shots per year are envisaged, bulb flash scores all round, but if the number is larger then electronic outfits merit consideration.  In my own case, I find a combination of the two very worthwhile, though it may be as well to point out some of the other advantages of electronic units.

The duration of the flash is very short - thus freezing action, water etc. very effectively, even with a focal plane shutter where flash synchronisation speeds may be comparat¬ively slow.  The colour temperature is normally higher than that of a bulb, giving a more correct colour rendering.  Electronic guns almost always have an open flash button (comparatively rare on bulb flash) and this is invaluable if a chamber is to be 'painted' with several shots or where shots entirely off the camera are required.  With the exception of the really powerful guns like the Metz 502 and the Braun F7OO/8OO range, most units take up the space otherwise occupied by two or three packets of bulbs or one P.F.100!

A wide variety of bulb flashguns exist.  The most compact, apart from the specialised cube guns, have folding reflect¬ors and are usually limited to cap less bulbs in A.G.1B, P.F.1B and P.F.5B/6B sizes. These cover most needs, but where large chambers exist P.F.60's or P.F.100's might be regarded as essential. Comparatively few guns handle these apart from the Bo-Flash already mentioned.  The Leitz gun with a folding reflector is a particularly useful model that does accept all bulbs, but this lacks a built-in firing button, which is a disadvantage.  The Kobold B. C. guns do have this provision, plus the ability to link two or three supplementary guns but they suffer the disadvantage of having quite large fixed bowl reflectors.

Of the smaller bulb guns, I have found the folding Japanese guns made by National to be excellent value, though the most suitable model, the Hyper B2, with built-in test bulb and open flash button, which sold for under £2 has now been discontinued and its replacement has not got the self firing device.  However, a number of B2’s are still available and its replacement (the PB 3S) is otherwise an excellent gun.  Other guns do exist at a slightly higher price with this facility, which is invaluable for multi flash pictures.  However, by means of a two or three way adaptors several small guns can be synchronised.

The comparatively recent introduction of the flashcube is also of interest.  Many small cartridge cameras now have a built-in rotating cube socket and some guns can be obtained which rotate automatically and so set up the next bulb for virtually instant use.

To sum up effectively on this subject is difficult without being subjective, but basically it would seem that the casual photographer would be very effectively served by a small bulb flashgun; while the more involved demands of recording photography for publication etc. might be better met by a combination of bulb and electronic. Certainly if electronic guns are miniaturised still further, it may well be that future enthusiasts will turn to these.

Editor’s Note:

The remainder of this interesting paper deals with choice of film, cameras, lenses and miscellaneous equipment.  It will, we trust, be published in the next B.B.

Members may also be interested to note that Alan Coase has a number of filmstrips for sale on CAVING AND POTHOLING TECHNIQUES (DW-154), CAVES: ORIGINS, DEVELOPMENT AND FORMATION (DW-153) and LIMESTONE LANDFORMS (DW-152 and 152E).

The double frame version, suitable for mounting as individual slides are at X.  £2.50 each with notes from DIANA WYLLIE LTD., 3,PARK ROAD, BAKER STREET, LONDON N.W.