Hints to Travellers, Scientific and General, Vol. 2 / Tenth edition, revised and corrected

by Royal Geographical Society

The traveller is recommended for advanced study of photography, such works as Instructions in Photography by Sir Wm. Abney, The Science and Art of Photography by Chapman Jones, and The Manual of Photographic Exposure and Development by Alfred Watkins, which may be had from any photographic dealer’s.

The aim of the traveller-photographer should be the production of good negatives. It often requires years of study on the part of professional operators (with advantages impossible to the traveller) before thoroughly good negatives are habitually produced; and it must not be supposed that a person taking up photography for the first time, in a few hurried moments before departure on a journey, will attain other than very unsatisfactory results.

The operations necessary for taking a picture are briefly as follows:—Having selected the position from which the view is to be taken (for valuable hints as to the artistic production of pictures see Robinson’s ‘Pictorial Effect in Photography’), the tripod stand is first set up, and the head approximately levelled by means of the pocket level, altering the position or length of the legs as may be necessary. The camera is next screwed on to the stand, and the lens selected which on trial is found to include the required amount of subject. For groups or portraits a long focus lens with wide aperture, such as Dallmeyer’s “Rapid rectilinear,” 11 in. focus, should be used. The next operation is to focus the picture accurately on the ground-glass screen of the camera. The focussing-cloth is thrown over the head and the camera, so as to exclude the light as much as possible, and while looking at the inverted image on the ground glass, the milled head of the rack adjustment is turned till the image appears as sharp as possible. The camera is now turned about on its vertical axis till it exactly includes the view intended to be taken, and the screw is tightened. It may be necessary to raise or lower the front of the camera carrying the lens in order to include objects at a high or low elevation; if the vertical range of this sliding front is insufficient, the camera must be tilted; but, if this is done, care must be taken to set the focussing-screen vertical again by means of the swing back, and to readjust the focus. The full aperture of the lens should always be used for focussing, and if the image is not sharp all over the plate it will be necessary to insert a diaphragm in the lens, using the largest that will effect the required object. Having then put the cap on the lens, the hinged frame carrying the focussing-glass is turned over, and one of the slides carrying the sensitive plates is inserted in its place. The slides should be exposed as little as possible to the light, especially avoiding direct sunlight; however carefully constructed, it is difficult to make them absolutely light-tight. The shutter of the slide is then withdrawn, and the exposure made by removing the cap from the lens for time exposure, and by a spring shutter for instantaneous work. The time of exposure must be estimated according to circumstances, and it requires considerable experience to judge of it accurately. A record should be kept in a note-book of every plate exposed, giving the number, date, time, exposure, subject, &c. If the plates cannot be developed the same evening, and the slides are wanted for fresh plates, they must be packed up again, and should be numbered. This is best done by marking the number on the back with a bit of dry soap, or in the film with a lead pencil. The image on the plate after exposure is latent and invisible, and has to be developed. This is effected by pouring on the plate, laid in one of the flat dishes, a dilute solution containing pyrogallic acid, soda, and potassium bromide. The excellence of the result largely depends on the due proportion between these constituents, and here more experience is perhaps necessary than in any other part of the process. The image having been fully developed, the plate is well washed, and then immersed in a solution of alum, which hardens the film. After another thorough washing it is “fixed” by immersion in a solution of sodium hyposulphite, which dissolves out the unchanged bromide of silver, and, being once more well washed, it is finished, and must be set up in the rack to dry spontaneously. On no account must heat be applied, not even the warmth of sunlight, or the wet film will melt. When dry it must be varnished to protect the film. The printing operations are best deferred till the return home, as they would involve the carriage of a large amount of extra apparatus. It is generally best to get the printing done by a professional printer; but if the traveller prefers to print from his own negatives he will find full instructions in each packet of paper which he buys.

Colour sensitive plates are now much used and, when a yellow glass filter is placed immediately in front of, or behind, the lens, will give in the print the same variations in depth of tint which the eye sees in the landscape, or other object. The nearest to perfection among these plates are those known as Panchromatic, but they must be developed in total darkness. The subject is a large one and should be studied in the pamphlets on ‘orthochromation’ published by Kodak (Wratten Division), and Ilford, Ltd.

As regards the expense of a photographic outfit, at the present time the manufacturing trade is still very unsettled, some goods cannot be supplied, and all have been greatly increased in price. Quarter plates which used to be sold at a shilling per dozen are now about 3s. 6d. Application should be made to the dealers for current prices.

The camera, slides and lenses may be arranged to pack into a solid leather case, conveniently in the form of a knapsack, measuring about 16 in. wide, 12 in. high, and 5 in. deep. This can easily be carried on the back of one man, and is of a more convenient shape than the cases generally sold for the purpose.

The plates and other apparatus, with the exception of the knapsack and its contents, and the tripod stand, are best packed for travelling in a strong basket, which is much better than a box, being more elastic and lighter. It will weigh, when packed with the apparatus, and a gross of 7½ × 5 plates, about 60 lbs.

Photography in Natural Colours.

It is now possible for the traveller to bring home records of what he has seen in natural colours. There are two or three known methods by which this may be done, but few are available for the work of exploration. The picture obtained by the method patented by Mr. Ives and named Krōmskōp Photography is produced by three monochrome images. These have however been taken through three tinted glasses in a camera of a special kind. The images may be thrown upon a screen by means of a special lantern; the light passes through tinted glasses of colours complementary to those employed in making the negatives with the result that the picture on the screen exhibits all the varied hues of nature. The devices however are exceedingly expensive and can be satisfactorily employed only by those who thoroughly understand the apparatus and the problems which have to be solved.

Simpler processes are the Autochromic and The Paget Colour Plate process. In the Autochromic process the manufacturers coat a sheet of glass with minute specks of three colours, blue, violet green and orange, irregularly spread, and lay a coat of panchromatic emulsion on top. The photographer exposes through the glass, thus obtaining a negative. The developed silver, the negative image, is dissolved away and the silver bromide remaining is developed giving a positive image in natural colours.