The Barnet Book of Photography.
by Various.
PREFACE.
[Ill.u.s.tration: THE BARNET BOOK OF PHOTOGRAPHY.]
_The purpose of this book is to place in the hands of every Photographer instructive articles on essential processes and manipulations, by eminent writers who have given such subjects their especial study, and who have borne in mind that whilst the experienced Amateur and the Professional may each find much to learn from a comparatively elementary description of methods and means, it is the Beginner who stands in greatest need of help._
_In the mind of every photographer the name of Barnet is inseparable from a great Photographic Industry, and now it is intended that the name shall be a.s.sociated with a good and useful book, which is called the_ BARNET BOOK OF PHOTOGRAPHY, _and it is left to the reader to say if the fulfilment of its purpose and the manner of its doing are such as to justify its existence._
_To all who are interested in photography, who love it for itself and for its productions, and who desire to improve their own practice of its many processes and applications, this Book is respectfully dedicated._
_Barnet, Herts._ _April, 1898._ _ELLIOTT & SON._
[Ill.u.s.tration: COPYRIGHT. NEGATIVE BY W. L. F. WASTELL. A FAMOUS PIKE STREAM. Contact Print on BARNET PLATINO-MATT BROMIDE PAPER.]
_Alpine Photography._
[Ill.u.s.tration]
Writing in London on a day in winter with a murky sky and sloshy streets, the t.i.tle of Alpine Photography is verily refreshing. It brings back days of sunlight and joyous experiment, and as we write the soul stirring scenery is before us called up by photographs taken under varying conditions of comfort and discomfort. That there is something different in Alpine photography to photography in our own country, we are bound to believe, since a special article is demanded for it.
The first question invariably asked is as to the nature of the outfit required. We should here like to divide our reply into two divisions.
The one concerning the mountaineer, and the other the ordinary tourist. For the former we have no doubt in our minds that a hand camera to take 1/4 plate or 5 4 pictures is the most convenient form of camera to take. It is not our business to advertise any person"s wares and we shall content ourselves by saying that personally we prefer a camera which has separate slides and does not possess a magazine, more particularly when gla.s.s plates are to be used, though a form of Kodak is not to be despised. But perhaps we are prejudiced in favour of gla.s.s plates, for they are simple to manipulate and have no c.o.c.kles nor other drawbacks which the careless photographer may have to encounter. Probably the most useful lens to employ is a doublet of which the focal length is about a quarter more than the width of the plate, since it includes a fair angle and the margins of the photographs are not likely to be markedly different in general density to the centre, as is the case when wide-angle lenses are employed. In England a lens which will cover with a large stop, say _f_/8, is a desideratum, but in the Alps it is very rarely that such a large ratio of aperture to focal length is required. As a rule for ordinary plates a lens has to be stopped down to _f_/16 to give a negative in say 1/50th of a second. Nevertheless where orthochromatic plates are to be employed it is very necessary to have a lens which will cover a plate satisfactorily with _f_/8 in order to use a colour screen for producing orthochromatic effects, since the loss of photographic light caused by the screen can only be compensated for by such an aperture even when the shutter is slowed down. The reader is therefore recommended on the whole to furnish himself with one of the modern lenses which work at _f_/8, though he must remember that the larger the aperture employed the more the margins and centre of the picture will suffer from unequal exposure. With some hand cameras there is a means of attachment to a stand, but a stand on a mountain is difficult to use and moreover has on more than one occasion been proved dangerous to carry. The mountaineer if he desires to give a time--and not an instantaneous--exposure on his excursion, would do well to have a small clip ready to attach to the head of his ice axe.
The axe will form a sufficiently stable stand for the more prolonged, but still short, exposure that he may be required to give on some particular subjects such as a photograph at sunrise or near sunset.
Photographers in England are rarely afflicted with breathlessness through exertion, but it is different in mountaineering. A mountaineer may keep his wind, but it would be rare to find that his heart was beating equably after some spurt of exertion, such as rock climbing. It is often after some such exertion that he comes upon some view which he may wish to record on his photographic plate. The usual method of holding the hand camera would under such circ.u.mstances prove a failure so far as sharpness of image is concerned. Pressed against his "middle" or "upper" chest, the beatings of the heart will record themselves on the photograph.
Under such circ.u.mstances resort must be had to some form of support on which to rest his camera. After many years" experience, the writer has come to the conclusion that there is no support superior to the ice axe. It is not necessary to cause it to stand upright in the ground, ice, or snow, though this should be done if possible. It will suffice to rest the point on the rock, and place the camera on the axe head, with the pick parallel to the body. We then have a firm support in one direction, and the hands, which are not affected by the automatic motion of the heart, can be trusted to keep it steady in the other direction. Photographs taken with a good lens, and with such a stand, will bear enlarging up to 22 inches, at least. It is because these photographs will bear enlarging that a small plate is recommended to the mountaineer. There is not a large proportion of Alpine views taken on the mountain side of which one would care to have anything but a memorandum, and it is such a size as that recommended which gives such a memento, and which, if desired, allows a more formidable size to be acquired at home, where we may suppose there are all the conveniences that a photographic laboratory affords. The writer has had experience on mountains with cameras varying from 12 10 to the 1/4 plate size. When younger and more inclined to waste a few valuable minutes of daylight in putting up a camera stand, the 12 10 gave pictures which we often lamented having taken, whilst in his more mature years, a snap-shot has never been regretted. The cameras which require stands, require one porter at least to carry them, for although the late Mr. Donkin carried his own 7-1/2 5 camera up the highest peaks, it is few men, who, even if they had the energy or the physique that he had, would imitate his example. A porter means an extra expense in fees, and an extra mouth to feed, and very likely entails slowness in a climb through having an additional man upon the rope. A quarter plate or a 5 4 camera the owner, however, can himself carry; but the best form of attaching it to his body has been a difficult task to evolve. Many and many different attachments have been tried. One thing is quite certain, and that is, the camera should be in a stout case, but it cannot be carried over the shoulders by a strap as we can do in comparatively level countries. Let anyone try to come down a rock with the camera slung over his shoulders, and he will soon find it dangling in front of his stomach, or swinging like a pendulum, and threatening to displace him from what at best may be a treacherous handhold. The method of attachment we adopt now, will be readily seen from the diagram.
[Ill.u.s.tration]
The shoulder strap is utilized, but a ring is attached to the back of the case as shown, and a strap or piece of whipcord comes over the strap as shown. The two shoulders are in AA and the case is carried as a knapsack. The length of the cord or strap BB is so adjusted, as is also the length of the shoulder strap, that the camera lies against the small of the back, and that it will not swing away from the body. At one time the ring was placed in front of the case, but the result was merely to cause the top of the case to rest against the back. The plan shown above has answered under almost every variety of circ.u.mstances, and the weight is inconsiderable. (A friend has his camera attached to the bottom of a small "rucksac" and this answers, but as the writer does not carry his own provisions or change of garments he has not adopted this plan). A long day"s march may be undertaken if this contrivance be employed, and the weight is scarcely felt.
For those who have not had extensive practice with hand cameras, a view finder is, if not a necessity, at all events, a great help. On the whole, perhaps the best form is that in which a miniature view falls on a ground gla.s.s. It must be recollected, however, that each view finder is adapted for some particular focal length of lens.
The view in the finder and on the plate should be compared, and if the former is more extensive, the surplus ground gla.s.s should be covered up with a black mask.
If it be determined to take a camera with its stand, very few directions are required beyond those which apply to ordinary view work on the plains. It may perhaps be as well to mention that a camera stand placed on ice or snow, is not immovable until the iron shoes of the legs attain the temperature of the surrounding snow or ice. An exposure of a few seconds will often show an image which has moved on the plate.
The next point that we may call attention to is the plate to be employed. With a hand camera there is no absolute necessity to have the most rapid plate, as far as exposure is concerned, but in mountain work it must be recollected that there are very great contrasts to represent on the print. "The slower the plate the steeper the gradation" is almost axiomatic, and it must be recollected that only a certain amount of opacity will print if the deepest shadows only are to be kept of the greatest black obtainable in a print. It is evident that the greater the range of light and shade that is obtained of a printable density, the more true to nature the picture will be. For this reason a quick plate with a moderate gradation is to be preferred--as being most generally useful--but it should be a plate which is absolutely free from fog, and it should also be of as fine a grain as possible, the size of which has something to do with development. This is still more true when a camera stand and hand exposures are made. With a slow plate with feebler intensities of light, which must be the case when the lens is stopped down to admit of hand exposures, the gradation becomes more steep than if a fairly bright light be employed. A quick plate does not suffer in the same way, however small the stop may be. It has already been stated that isochromatic plates may be employed with a hand camera. For ice and snow views there is not much to commend their employment, unless to give a deeper shade to the sky and to the vast creva.s.ses which so often form part of the foreground. The darker sky allows faint clouds to be visible in a print when they otherwise would be absent. Pictorially thus the isochromatic plate has something to recommend it. Celluloid films have often been subst.i.tuted for plates by the writer, and excellent photographs have been obtained on them when they were fairly rapid.
There is not much to be said in their favour as regards weight, for in most cameras the support for them weighs nearly as much as the gla.s.s plate. There is also a disadvantage in developing them, for they are not so easily manipulated as a rigid body. For convenience in travelling, however, they are to be highly commended. A gross of cut films do not weigh so much as a dozen plates and occupy much less s.p.a.ce in the baggage. The question of the use of a Kodak camera with its roller slide, has not been brought forward, not because excellent results cannot be obtained with it, but simply because the writer prefers to use plates and films which can be got at any time for the purpose of development.
For travelling on the continent, and to one"s mountain destination, experience has shown that a small hamper is the safest receptacle of all the necessary kit. A hamper which will contain two camera cases side by side is really sufficient; but it should be a little greater in depth. It may be thought that two cameras are to be taken, but such is not the intention. If a zinc trough be made of the size of one camera case it will contain all the developing apparatus necessary, the lantern, and the plates or films, and all the few etceteras which go to make one happy. (A screwdriver, a file, and some extra screws, and gummed paper and white blotting paper cut to the size of the plates should be enough for the etceteras). The hamper may be arranged so that the camera and view finder may be taken out without any derangement of the rest of the articles in it.
The developing bottles and cups, with the dishes, may be similarly extracted. This prevents undue trouble in unpacking and packing. One grand thing to remember is, pack well but not distressingly tightly, in other words don"t employ an expert packer if you wish for comfort.
Have the hamper a size too large rather than a size too small. Also be it remembered that it is useless to stopper the bottles with all sorts of devices at home, and have to pack in an ordinary manner when once the contents of the hamper have been brought into use. Have your bottles covered with an indiarubber cap which can easily be removed and replaced; of course we are a.s.suming that development is to take place during one"s travels, and not to be left over for home.
Personally we think that a speedy development after a view is taken will give the best picture. It may often happen that an undeveloped sensitive plate or film will suffer by its travels. There will or may be scratches and what not, which would be absent if the negative is finished at the time. The outfit for development which need only be taken is as follows: four developing dishes, bottles or cartridges of the dry developer, ammonia diluted to half its strength in a gla.s.s stoppered bottle (if in a wooden case, as for medicine bottles, it will be a further protection), a couple of tins of hyposulphite _pounded up_ before the journey, carried in small tins (such tins as the half-plate platinum paper comes in are very convenient), two or three empty six ounce medicine bottles with good corks, a two or four ounce measure, a washing rack with a trough (there is a folding rack in the market which answers admirably; it has =v= shaped grooves which never damage the edges of the film, and one rack will take twenty-two gla.s.ses back to back). A zinc trough can be made to cover the plates with water when in the rack, a lantern (by preference a paper folding one), a dusting brush, a couple of dusters, and blotting paper cut into squares the size of the plates, with which to pack them--it is useful also to have spare pieces of blotting paper to place beneath the plates when drying, also a piece of mackintosh to place on the wash stand during developing operations--an empty pint wine bottle will be got at any hotel and in this the hyposulphite can be dissolved. The list looks formidable but the whole can be readily packed in the hamper of the size given. It will be seen that no intensifying solutions are enumerated amongst the requisites. A negative is better strengthened in the quiet of one"s dark-room at home.
[Ill.u.s.tration: HOMEWARDS. KARL GREGER.]
Now we must give a hint or two as to the exposures required. We will suppose that on the plates to be used a satisfactory negative of an open English landscape, on a bright June day with fleecy clouds in the sky, can be secured with an aperture of _f_/11 in 1/25th of a second. If that be so, then on an equally fine day in July or August, at an alt.i.tude of about 6000 feet, the same kind of view should theoretically be secured in 1/50th second, and a stop of _f_/16--that is, the photographic light is about four times as strong. It must, however, be recollected that at this alt.i.tude, and particularly near mid-day, the shadows are not illuminated to the same degree from the sky. The darker blue sky shows that the light which at a low alt.i.tude goes to make a pale blue sky is to be found in the direct rays of the sun, and not scattered to give a luminous sky. As the shadows are princ.i.p.ally illuminated by the light from the sky, it follows that the shadows will be darker at a high than at a low alt.i.tude, for this reason amongst others, the exposure should not be curtailed to the amount given above. If the aperture be reduced to _f_/16 it is probable that the exposure of 1/25th second will be not more than sufficient to give. For our own part we prefer to give longer and to expose well for the deep shadows, trusting to development to give us properly "gradated" pictures. As the sun goes down toward the horizon, the shadows get more illumined from local reflection, and it is scarcely necessary to alter the exposure until considerably nearer sunset than at home, when the exposure must be considerably prolonged. For views in which there is little but ice and snow, the exposure should be very much curtailed.
There is so little contrast that if the exposure be at all prolonged the picture will be inevitably flat. The shadows are illumined by an immense quant.i.ty of light reflected from the white surface, and the difficulty is to get sufficient contrast. The writer well remembers one set of beautiful views, taken from the top of a mountain some 10,000 feet high, where the eye could see nothing but snow-fields and ice and swirling ma.s.ses of clouds. The day was not bright, but to get a satisfactory picture a stop of _f_/32 was necessary with only an exposure of 1/70th of a second. Plates given an exposure of 1/25th second with a stop _f_/16 showed little besides a plain white ma.s.s. It would be difficult to give hints for every kind of view.
The judgment of the operator must be brought into play and no actinometer will be of much use under the varied conditions which are the rule, not the exception.
Now as to development. The "one-solution" given by the metol and amidol cartridges are the most readily prepared, and in five times out of six will scarcely be bettered, but for the sixth time may fail, because of their "rigidity." For these exceptional negatives, solutions of an oxidizing agent such as pyrogallol, of a restrainer (bromide), and of an accelerator are to be recommended. For the latter, the carbonate (not the bicarbonate) of potash is much to be recommended, though some prefer ammonia. Two formulae are given, either of which will be found extremely useful. When the exposure has been prolonged enough for details in deep shadows to be brought out, it will generally happen that over-exposure has been given to the high-lights, and it is to keep these in the printing state that care is required. In the old collodion dry plate days, it was very usual to bring out a complete phantom image of a subject before any density was given to it. When this was properly out, the intensifier of silver nitrate and pyrogallol was applied, and the picture gradually brought up to printing density. It was usually full of detail in the high-lights and shadows, all of which would be found in the finished print. Such is the same procedure which we recommend, strive to get out an image of feeble density but full of detail, and then give the density.
The plate should first of all be thoroughly soaked in a solution of the alkali which can be used, and then a few drops of the pyrogallol solution be dropped into the developing cup with an equal number of drops of the restrainer. The alkaline solution is then returned to the cup and again poured into the dish and over the plate. By degrees the required phantom image will make its appearance, and now bromide and pyrogallol are added until it is evidently complete. The plate is then washed in water, a final wash being given in a very weak solution of acetic acid or citric and water. After a final rinse with water the plate is treated with the pyrogallol solution and restrainer in the proportion recommended for the ordinary development of the plate, omitting the alkali. The density will begin to appear, and when it flags, a little alkali is added (a few drops at a time) to the solution. Keep the image fairly feeble at above half the proper printing density, and fix. The plate should then be kept for intensification, preferably by Mr. Chapman Jones"s, when a mercury solution is applied, and then a ferrous oxalate to reduce the latter to the metallic state. It will be found if this procedure is adopted, that the negative is built up with a greater range of light gradation than by bringing it out by a one-solution method of development. If one wishes to exercise artistic treatment, then in the preliminary stage more importance can be given to any desired part by applying a camel"s hair brush soaked in normal pyrogallol solution with its restrainer. The prominence thus gained will be kept in the subsequent operations. When applying the brush care must be taken that the image blends as it were with the rest of the picture. No abrupt increase of density must be permitted, as if it be, the result will be anything but satisfactory.
The following is an ammonia-pyro developer, with which the writer usually works.
A Ammonia 1 part.
Water 9 parts.
(Of course, should the ammonia be taken half strength allowance must be made for the dilution.)
B Pota.s.sium bromide 20 grains.
Water 1 ounce.
(When travelling it is very convenient to have the bromide weighed out into 20 grain packets.)
P Pyrogallol dry.
S Saturated solution of sulphite of soda.
When the view has strong contrasts and the plate has been exposed for the shadows take of A 30 minims and 2 ounces of water and soak the plate in it as given above. Then add to the cup, of B 2 drams, of S 1 dram, and about quarter grain of P. Pour back the solution of ammonia from the dish, and then apply the mixture till all detail appears, and proceed as indicated above. A saturated solution of pota.s.sium carbonate may be subst.i.tuted for the ammonia solution.
Before closing this chapter it may be of use to the reader to tabulate the number of thicknesses of atmospheres through which light has to travel at different alt.i.tudes of the sun at sea level.
Alt.i.tude. Atmosphere.
90 1.000 80 1.015 70 1.064 60 1.155 50 1.305 40 1.555 30 1.995 20 2.904 15 3.809 10 5.571 5 10.216 4 12.151 2 18.882 0 35.503
If sunlight outside the atmosphere be represented by 1 and say 1/10th be cut off by 1 atmosphere, then after transmission through 2 atmospheres only .81 will reach the spectator, and if through 3 only .729. For any atmosphere the diminution will be 1/10th, that is, it will be .9^_x_ where _x_ is the number of atmospheres.
If we ascend the factor varies, there are less thicknesses of atmosphere to go through and we get the following table.
Photographically Visual Transmission Actinic Light Barometer (Sunlight outside Transmitted in Inches. the Atmospheric (Sunlight outside being 1). the Atmospheric being 1).
30 .853 .639 29 .866 .654 28 .875 .672 27 .884 .689 26 .891 .708 25 .899 .730 24 .908 .746 23 .915 .763 22 .922 .787 21 .928 .800 20 .934 .819 19 .940 .833
This table and the preceding one will enable a calculation to be made as to the exposure to be given. Thus at sea level with a photographic brightness of sun of 639,000 candles when nearly overhead, it will at 5 above the horizon only have a photographic brightness of about 1000. At about 9000 feet high the photographic brightness would when the sun is overhead be about 800,000 candles, and at 5 it would have a value of 350,000, showing the greater penetration through the thinner atmosphere.
_W. de W. Abney, C.B., F.R.S., etc., etc._