Thursday, June 5, 2008

Practicus In The Studio: Printing Processes For Portraiture.

           I find that nowadays people are rather apt to get into a groove over their printing methods and apparently forget that any other process exists except that which they happen to be working. It thus occurs to me that a brief review of the Different printing media at present available, with notes on the characteristics of each, would be of service to those who wish to vary their work.
           The uncertain character of daylight in Great Britain has made bromide and gaslight papers very popular, and an overwhelming proportion of portrait work is now produced upon them, but thanks to the almost universal supply of electric current, we are not now altogether dependent upon daylight for what may be generally classed as "printing out" as distinguished from developing processes.
           The quality of the negative is an important factor in the production of the print, and only a small proportion of current negatives would yield even a passable result upon the old albumenized paper which for many years was almost exclusively used, so much so, in fact, that a print was hardly regarded as a "real" photograph unless it was made upon it By reason of the quality of the negative required, and because it was impossible to produce it by modern factory methods albumenized paper is now only a memory, and it is impossible to procure even a small quantity through the ordinary channels. Hence it is unnecessary to touch upon it otherwise than by way of reminiscence. Bromide paper in its various grades has taken its place, and I therefore put it first upon the list as being the process for the million, or that proportion of it who practise photography.
           Although in such general use, few portraitists fully appreciate the wonderful variety of surfaces, speeds, and character of emulsions which are available. I cannot fairly allude to any specific makes by name, but will be content to refer my readers to the advertisements in the B.J. Almanac, and the advertisement pages of the weekly Press. Bromide papers may roughly be divided into several groups, although these somewhat overlap each other. We may divide them by speed, that is to say, the time necessary to produce a print from a given negative by a given illumination; by the degree of contrast which can be obtained from the same negative by the surface texture, and by the colour of the paper base itself apart from the image. Thus we have "slow" and "rapid" papers, hard or contrasty, and soft, rough, smooth "platino matt," "satin," and glossy, these giving a range from rough drawing paper to a surface like glass. In many cases certain grades come into two or more of these classes. Thus we may have rough rapid, smooth rapid, hard cream and soft cream, and the same in white. In this great variety lies one of the principal advantages of bromide paper, for there is hardly a negative which is capable of being printed at all for which a paper which will give the best result cannot be found. Many printers use only one variety of paper, and trust to their skill in exposure and development to produce even results from all classes of negatives, but from experience I can assert that a very ordinary worker can produce a better result upon "hard" paper from a flat negative than an expert can upon the average kind. Therefore I advise every printer to have by him a small stock of special papers, so that he can at once select the quality necessary for exceptional densities of image. While not recommending this course to he carried too far and to encumber one self with too many kinds, I would point out the influence of colour and surface in certain cases. Suppose that we have a hard, chalky negative; we can use for this a "cream crayon soft" paper. This not only reduces the contrast of the image but tones down the glare of the whites, while the slightly rough texture gives further aid me direction. With a very soft negative we may choose a satin surface paper, that is, one with a semi-gloss, which gives a richness to the shadows. A full gloss paper would be even better, but for high-class -work a glossy surface is rarely acceptable. Further modification may be obtained by toning the image to a sepia colour, a course generally advisable with harsh contrasts, as brown and white usually gives a softer result than black and white when both print are of the tame quality. I strongly the practice of toning bromides irrespective of quality; every day thousands of prints which are of fatrly good quality in black and white are spoiled by being converted into poor, flat, rusty sepias. If I have the slightest doubt as to the resulting tone of a print I would- leave it in black and white, and if the order were for sepia prints I would ask permission to submit a black and white print when sending the proofs.
           Gaslight papers closely resemble bromide in the points I hare already mentioned, so that it is not necessary to deal with them at length. I should like, however, to say that besides the "contrasty" qualities which are most used, are special kinds which, though very slow in action, walls give splendid results from dense negatives. These papers require a very strong light for printing, several fifty-candle-power lamps being needed in the printing boxes.
           Gelatino-chloride or P.O.P. was not o long ago almost universally used for portrait work, but is now little in favour, especially among the cheaper class of studios. A few good class firms still find that the warm tones so easily obtained upon it are acceptable to their patrons, and wisely adhere to it. Certain warm browns and reddish tints closely approach the delicacy of carbon, and will always be popular, but the purple black tones are now quite out of fashion, P.O.P. requires much greater cart- and cleanliness in working than bromide, which may account for the latter superseding it.
           Self-toning papers, which are mostly collodio-chloride, possess many advantages, although they are the slowest of the printing out sort. This defect may be largely overcome by employing an enclosed arc for printing, when the time in much shortened. A great range of tones from warm sepia to a blue-grey may be obtained by variation of the strength of the hypo bath and for the grays a preliminary soaking in a solution of common salt. Matt and glossy surfaces and white and cream bases are available in this class of papers. A variation of tone may be obtained by using a platinum toning bath as employed in the doable toning of ordinary collodio-chloride paper. I hare used much of this paper, and find that the prints stand very well. Some, which are fifteen or sixteen years old, seem quite fresh. Self-toning gelatino-chloride is also made, but I have not found so good a range of colours with them as with the collodion. Moreover, they cannot be dried by heat, as the latter can. Some few photographers have used what is termed salted paper for large work. This has to be prepared at home by coating drawing paper with a solution of chloride of ammonium or even common salt, and floating upon a bath of nitrate of silver. The prints may be fixed without toning, or they may be toned in any of the gold baths used for P.O.P. Strong negatives are required, as the image is inclined to be rather dull as compared with that on an emulsion paper. The surface is very agreeable, and with suitable subjects the results are highly artistic. Platinum printing like carbon stands in a category of its own, and occupies the first place with those photographers who put quality before cost. It is, next to ferro-prussiate, the simplest of all printing processes, and is not only pleasing but permanent; it is actually a "thing of beauty and a joy for ever." Platinum papers can be obtained in rough and smooth surfaces, end on white and cream bases. As there is no practically useful method of toning, special papers and solutions are prepared for black and sepia prints respectively. One important quality of platinum prints is their absolute flatness when finished; as there is no coating either of gelatine or collodion there is no risk of curling, and if attached by one edge to a mount they will lie close to it no matter what the condition of the atmosphere may be. It should be clearly understood that the word "platino," when applied to bromide paper, refers to nothing but the appearance of the surface. There is no platinum in the coating, and the image is no more permanent than that on ordinary bromide papers. Carbon printing is unique as regards the great variety of colour and surface in which prints may be produced. Although in portraiture only two or three are commonly used, such as sepia, red chalk, and warm black, at least fifty varieties of colour, including reds, blues, greens, browns, grays, and many others, and a score of different weights and surfaces in the transfer papers are regularly supplied. So that it is possible to make carbon prints which closely resemble those by any other photographic process; and, needless to say, all are absolutely permanent. It is worth noting that, in spite of war restrictions, the price of carbon materials has shown but little increase in price. Many are deterred from attempting carbon printing by the idea that it is very difficult, but this is not the case if ready sensitized tissue be used, and if the work be carried out systematically it is little more troublesome than P.O.P., and the extra price obtainable will amply justify the additional work.
           I have carefully abstained from giving working details of any process, us this has been done over and over again, out in case of any difficulty, any desired information will be given through the usual "Answers to Correspondents" column. My object has been to point out what materials photographers have to hand for the production of such prints as may be needed for any claw of business.



           Some people say that "appearances are deceptive," and others that " the first impression is everything." Although these dicta are apparently contradictory, there is truth in both, and our resent object is to point out how outward appearances react on the success of a photographic business.
In photography more than in most businesses the impression made upon a prospective sitter is of the greatest importance. A shabby exterior, a dark and uninviting approach, or a dingy, untidy reception-room will probably act as a deterrent to the better-paying class of customers. The visitor will go no further than to make an inquiry as to prices, and retire as quickly as possible. This fact is more readily realised by women than by men, and may account for the fact that many women have started successful studios, while men who could turn out better work have failed to attract patronage. To the woman the trimmings are of primary importance, and she starts fitting-up her premises with much the same idea that she has in furnishing a home – that is, to make it an attraction to others and a source of modest pride to herself. Now it is not necessary to go to work in an expensive manner to achieve this end; the only tiling necessary is to start with some definite scheme, and to keep it in view throughout. As the first contact with the public is usually by means of the showcase or window, we must start with that, and endeavour to make it as bright and attractive as possible, and always keep it so. Many places have been opened with an imposing array of plush and gilding, which for lack of care has in a few months become faded and dingy, giving the impression that no business is being done; while others started on more simple lines have by constant change and scrupulous cleanliness continued to attract the favourable notice of passers-by. Supposing that we succeed in doing this, the entrance and staircase, where there is one, should be respectable and well cared for. Dirty walls, with the paint or paper peeling off, worn linoleum, and dirty windows do not lead people to expect clean, artistic work behind them. This can all be remedied at small cost, and should at once be done where such a state of affairs exists. Many old-established photographers have experienced a serious drop in their takings when a rival concern has opened near them, not because the work was better, nor even as good, but because it was put forward in a more attractive way.
           The reception-room is often allowed to degenerate into a sort of rubbish store. Obsolete furniture from the studio, parcels received or ready for despatch, frames, and out-of-date specimens cover the tables and chairs and utterly destroy that appearance of daintiness and comfort which is so necessary to the production of a complaisant mood on the part of the visitor. One old photographer always called his reception-room the drawing-room, and always kept it quite free from business lumber. Even his specimens were kept out of sight until they were required, the comfort of his patrons being apparently his sole aim. Others have made their reception-rooms interesting and profitable by displaying paintings, rare furniture, and curios, which not only served to pass the time while waiting, but which were ultimately sold. While on this subject it may be worth pointing out that the personal appearance of the proprietor and his staff should be as carefully looked to as the other decorative items. Photographers used to have a reputation for slovenliness, and it is to be feared that some still merit it. They should take a lesson from the jeweller and other tradesmen who have to deal with ladies, and not appear in frayed, chemical-stained habiliments, while their assistants should be trained to those habits of neatness in dress and person which are expected to be found in a good-class business. One lady photographer insists on a uniform style of dress on the part of her receptionists, but this is going a little too far. Still, it is better than a tawdry blouse and a faded alpaca apron, which have been seen in studios of some pretensions.
           The studio is a workroom, and need only be kept scrupulously clean and free from unnecessary lumber. The camera and stand should be kept well polished even if of old pattern, and anything in the way of greasiness on the furniture avoided. Velvet and leather chair-seats need keeping in order, as a lady does not like to risk soiling a nice dress. We have seen a lady refuse to sit on a greasy-looking chair, while others doubtless shuddered when they did so. The fittings of the drawing-rooms should be inspected daily, combs and brushes frequently washed, and a white drugget kept ready for use for wedding and evening-dress sitters. If powder and cosmetics are furnished , the pots and bottles should be kept free from smears and dust; actresses may tolerate dirty “make-up,” private sitters will not. Nothing succeeds like success, and if trade is quite the world must never know, for people like to feel that they are patronizing a fashionable establishment, even if they have to wait for their portraits. One of the most successful American portraitists has told how at the beginning of his career he found sitters were not as numerous as he had hoped for, so resolved upon a bold stroke. He filled his diary with imaginary appointments for a fortnight ahead, and declined sitters who would not wait for a vacant date. At the end of the period he had booked more genuine appointments than he had ever done before, and since then he has never looked back. When anything is difficult to obtain people are sure to want it, and when the sitters who had booked told their friends how terribly busy Mr. So-and-so was, they immediately felt that he was the right man to go to. Few British photographers would care to take such a risk as our American friend did, but it is well to keep up the impression that business is flourishing, and that it is only as a special favour that early delivery can be promised.
           One little matter must not be overlooked, that of stationery. We receive many letters upon notepaper the quality and printing of which would disgrace a chandler's shop. When people contemplate patronising a self-styled artist they are apt to judge his artistic skill by the style of the communications he sends to them, and nothing is so, detrimental as poor stationery. We do not advocate florid designs or bizarre colouring the simpler the better but the type should be artistic and the paper as good as we can get in these times. The money so spent will not be wasted. It is only invested, and will return increased a hundredfold before many days. The whole point is this that the photographer must appear to have some self-esteem and confidence before he can expect the public to trust him, and therefore should make as good an all-round show as circumstances permit.

EX CATHEDRA: Stained Negatives; A Business Accessory; Photographic Apparatus at Auction Sales; A Home-Made Camera Case

Stained Negatives.

           We suppose that by far the greater majority of stained negatives which are sent to us for a diagnosis of the defect represent the result of incomplete fixation. Unfortunately a remedy for the brownish stain which is the product or insufficient treatment of the emulsion with hypo is an almost hopeless problem in comparison with such general stain which comes from development or even the patchy stains due to contact with a printing paper containing soluble silver. About the only suggestion which we can make for the removal or, at any rate, partial remedy of fixation stains is to intensify the negative with mercury and ammonia, or with Monckhoven's formula of mercury and silver cyanide. By either of these processes the yellowish stain is converted into a grey one 01 little printing value, and with the aid of a certain amount of local reduction of the intensified negative it is possible in some cases to arrive at a respectable result, but whenever circumstances permit of a second exposure being made, the making of another negative is the only remedy which should be thought of. The silver stains from damp paper are of rarer occurrence in these days of development papers, yet it may be added that a ready means of removing them is that of Mr. Harold Baker, of rubbing with Globe metal polish and then leaving for a sufficient time in a strong solution of hypo. This is a very much better and safer plan than the iodide and cyanide method, the drawback of which is that the solution attacks the image proper as well as the deposit of silver stain, and therefore calls for an exceptional degree of expertness in its application.

A Business Accessory.

           "A place for everything and everything in its place" is one of those maxims of our childhood on which too much importance cannot be laid in any business establishment. The waste of time and the mental irritation which arise from the inability to find something which "you know is there all the time" and is only hiding itself through some diabolical malice, are elements which one tries to eliminate from the day's work. Partitioning of drawers and cupboards and a system of labelling the places where articles in frequent use are to be put when they are finished with will go far to removing these causes of reduced output in the normal working hours. But the suggestion we have to make and it is one of which we have proved the utility relates to a means for preventing the straying of the odd messages and memoranda which are part of the machinery of any business. It is simply a place where notes that such-and-such an order is wanted urgently, or such-and-such a chemical is getting out of stock may be placed so that they cannot be overlooked; where, in fact, which is the important thing, they will be looked for. In our own office routine, which calls for many reminders, this takes the form of a good sized board covered with soft cork lino and provided with a supply of push pine. These serve to fix in an instant any memorandum which .needs to be displayed to view until it is dealt with. The board speedily becomes an institution to which one looks and which soon largely replaces verbal messages. It seems to us that good use could be made of one or two of these devices in businesses, such at that of photographic portraiture, where there is much reference from department to department.

Photographic Apparatus at Auction Sales.

           A short time ago we commented upon the advisability of intending purchasers of second-hand lenses being very careful to see that the lens offered to them in a certain mount was actually the instrument issued new by a particular maker. We recently heard of an experience in connection with lenses which goes far to point out the importance of the buyer knowing fully what he is purchasing. The case in point was en auction sale, and among other things, household furniture, etc., two lenses by a well-known maker were catalogued. A photographer whom we know attended the sale, and after having previously examined the two instruments to his satisfaction, though he was not aquatinted with the particular type of lens, bid for and purchased them for what was a fair sum. Of course, a trial upon a camera was not permissible, and his surprise may be judged when upon testing one of the instruments very indifferent definition was given. At some trouble the photographer got a catalogue illustration by the makers of the lens, and upon comparing the plan with his own instrument he found to his surprise that one of the components of the original instrument was absent altogether, which fact was made all the worse because the maker had long ago suspended business. And at a time like the present no others would be likely to take on such a job as supplying the missing component, even supposing such a thing was possible. This note is penned as a warning against those who may be tempted to buy photographic goods at general auction sales, which do not admit of a proper trial of the instruments catalogued. Such may turn out the reverse of a bargain, and as a general rule the purchaser has no redress, since most auctioneers in their conditions of sale hold themselves under no guarantee against errors of description.

A Home-Made Camera Case.

           Now that any goods of leather are so expensive it may be of service to some if we refer to a case for the camera outfit which we saw the other day for the making of which the photographer had used a substitute for leather which yielded a solid and yet slightly lighter case than that material. The case was made of ordinary three-ply wood, with a division for the slides, and the lid was fitted with lap-over edges in the same way as the best leather cases are made. The inside may be lined with thick green baize or thin felt, obtained from any upholsterer in a large way of business, and fastened with small gimp pins obtainable from the same source. The outside of the case was finished with a covering of good waterproof canvas fixed in position with dextrine paste, obtainable at any shoe or leather sellers, the edges of the canvas being turned over and fixed in position with the gimp pins before mentioned. To the bottom, four “Domes of Silence” furniture castors were fitted to keep the case off the ground, and so to reduce damage by its being placed for any time on wet ground. The case was made for less than a quarter the cost of one in solid leather, and weighs a few ounces lighter than leather case of the same size. Provided the joints are firmly screwed there is nothing to fear on the score of solidty. Moreover, such a case allows a more substantial lock and hasp to be fitted than if the article were made of the ordinary stout leather.

Wednesday, June 4, 2008

Practicus In the Studio: Artificial Lighting.

           It seems only a few years ago that a photograph taken by artificial light was somewhat of a curiosity and, with one or two brilliant exceptions, photographers were apt to regard it as a poor substitute for daylight, and, to tell the truth, the work generally produced quite justified their opinion. That I need hardly say was a time when electric mains were unknown, and the photographer who wanted to use the electric light had to install an engine and dynamo in his cellar or else to burn “white fire” in a specially built lantern, the precursor of the modern flashlight. The platen were then much dower than modern ones and the candle-power of the light much less, so that there was a tendency to reduce diffusion to a minimum, and chalky faces and black shadows were the usual thing. I mention these old times because there are still many people who imagine that there must be something inherently different between daylight negative and an artificially lighted one, and that the latter needs some sort of apology. This is quite a mistaken idea, and anyone who holds it should make tip his mind so to improve his work that even an expert should not be able to tell the difference.
           Before dealing with any of the types of installation which are now on the market, I should like to impress upon my readers that there is no essential difference between day and stifled lighting as far as effect is concerned – that is to say, that a top-light will give sunken eyes and hollow cheeks, a low side light will give the contrary effect, that an unscreened light gives the effect of direct sunshine, and that a well-diffused electric light gives much the same effect an ordinary daylight. This gives the key to successful lighting, for if the operator will carefully note the position of his dominant light when using daylight he can produce practically the tame effects with any other illuminant if he places it in the same position with relation to the sitter.
           The most important problem is that of diffusion, or one might say distribution, of the light, and the difficulty is greater or less as the original source of light is small or large; a single pair arc is the most difficult to manage and a battery of half-watts or small enclosed arcs is the easiest. Still the single large enclosed arc is not to be despised: I never feel unhappy with one at my command, therefore I will start my detailed instructions with this instrument.
           The enclosed arc is an ordinary single pair of carbons enclosed in a glass cylinder so as to be practically airtight. The effect of this is that a much longer arc can be maintained. A long arc emits more violet rays than a short one, consequently shorter exposures can be given. Incidentally there is leas consumption of the carbons, so that the lamp does not require much attention. An ordinary street lighting arc enclosed in a ventilated globe n classed as an open arc and must not be confuted with the enclosed arc properly o called. The difference between the various types of enclosed arc lamps is in the feed mechanism only and not in the light: with a given diameter of carbons and quantity of current you will obtain the came amount of light if your cylinders are kept clean. I hare worked continuously with the Westminster, Jandus, and Aristo lamps, and have found them all satisfactory. I think I have tried every reflecting and diffusing device on the market, and have come to the conclusion that the simpler the arrangement the better. My shade or diffuser - call it what you will - is made of two wooden hoops about 36 ins. across connected by four laths about 46 ins. long. Round these are bent thin cardboards so as to make a cylinder open at top and bottom with one-third left open. The inside of the card is covered with dead white paper (if white cards are used this is not necessary) and the outside with dark paper or cloth. The open third is now covered with tracing cloth, and the whole attached by cords to the chain or shackle from which the lamp hangs. It is a good plan to fasten the tracing cloth with push-pins so that it can be easily removed when the carbons have to be renewed or the glass cylinder cleaned. If possible the lamp and shade should be adjustable for height, so that it may be lowered for sitting figures and for children, it being always remembered that a foot or 18 ins. difference in position may mean 20 to 40 per cent difference in exposure. With this shade I have found no other accessories necessary, beyond an ordinary round screen, which I nearly always interpose about halfway between light and sitter, leaving the lower part of the figure unshaded, and the usual white reflector. I have sometimes hung a dark curtain or vallance to the edge of the lamp-shade to avoid a glare into the lens, but this is not always necessary.
           Open arc lamps are usually so fitted that only reflected light is used, the best known type, Marions Northlight, bane very similar to the original Van der Weyde model, but fitted with several pain of carbons to reduce exposure. The arcs are screened by a metal reflector on the sitter's side and the light reflected from the [whitened inside of an umbrella about 4*(1/2) ft. in diameter. The surface of this may be regarded as a brightly lighted window, and any necessary diffusion provided for with the head screen already mentioned; the reflector is, of course employed as needed. The highest type of work has been done with this system of lighting, the only drawbacks being a larger consumption of carbons and current than is necessary with the enclosed arc, while the large umbrella reflector takes up a good deal of apace in a small studio.
           Although there have been several other systems of arc lighting before the photographic public, the foregoing are practically the only survivors, and they will have a hard struggle for existence against the nitrogen-filled or "half-watt" lamps which are making rapid headway as the simplest and least expensive of any system which has yet presented itself.
           Before proceeding to these I should like to touch upon another form of electric lighting which has many good points: the mercury-vapour lamp. This is easy to manage, requiring no attention, and is economical of current, while owing to the large area over which the light is spread the lighting is fairly soft. Its one defect w it colour, which is greenish, and this gives anyone exposed to its rays a somewhat ghastly appearance. This can be overcome and the lighting improved by hanging a thin pink curtain in front of the tubes; this not only tones down the green but acts as a diffuser. As the tubes are somewhat long the lower part of the light tends to flatten the features somewhat, and I have found it advantageous to have the upright support lengthened, so that the bottom of the tubes are 4*(1/2) to 5 ft. from the floor. The tubes are rather fragile, so that care must be exercised in moving the apparatus about. Especial note must be taken of the connections so that the polarity is never reversed, or disaster will follow. It is easy to make such a mistake if a wall-plug is used, and some means should be taken to make it impossible to put the plug in the wrong way.
           The half-watt lamp as made for photographic work closely resembles the ordinary metallic filament lamps used for domestic lighting, but is much larger than these usually are. Its distinctive feature is that instead of the interior being as nearly a vacuum as it is possible to get, it is filled with an inert gas such as nitrogen, which, greatly retards the volatilization of the filament when the lamp is run at a high voltage. Most people know that if a lamp be run at an appreciably higher voltage than lit is made for the light is rendered much more brilliant, but that the life of .the lamp is shortened to a few hours or even a few minutes. Owing to their construction the half-watt lamps have practically the same life as the ordinary type, while the light is rendered white enough to enable short exposures to be made in the studio. The General Electric Company has devoted considerable attention to the photographic aspect of half-watt lighting, and send out not only suitable bulbs, but reflectors and stands ready for studio use. I have worked with several installations of half-watt lamps, and can recommend them to any photographer requiring a new installation. The lamps are made in various candle-powers from 500 to 3,000. I prefer the 1,000 c.p. as the best unit. If six 1,000 c.p. lamps be taken as the maximum power needed for ordinary work, these can be so spread out as to cover a considerable area and to give sufficient softness with very little loss of light by diffusion. If two 3,000 c.p. lamps were installed they would be as powerful as two arcs, and would have to toe placed farther from the sitter and a thicker diffuser would be needed. The metal reflectors supplied by the company are convenient and a great protection to the lamp, but I have found the light rather too concentrated, and have always fixed a thin white nainsook curtain in front of them. They can be fitted with a counterbalance weight like a grocer's scales, so that they may be raised or lowered to any desired height. A cheap method of fitting is to make large D-shaped reflectors of white card with a front of nainsook. The most useful size is about two feet wide by thirty inches high for the nainsook front, and eighteen inches deep from the centre of front to the back. One must be careful to place the lamp well in the centre, as there is a considerable amount of heat from the lamp, and if too near either lamp or calico one or the other will be burned. Light weight tinplate can, of course, be substituted for -the card for a permanent installation. I used the card lanterns for six months, and got one slight scorch only.
           With regard to the arrangement of the lamps it is difficult to give precise instructions, and in accordance with my previous remark I recommend them to be placed so as to allow the light to fall upon the sitter at the same angle that daylight usually does. As it is undesirable to place them between the daylight and the sitter they should be placed on the dark side of the roof in the same position as the open portion of the light. If it be desired to light the same side of the face as with daylight the lamps should be placed towards the other end of the studio and the camera turned round. For average lighting the lamps should be fixed so as to rise to eight feet from the floor for standing figures .and groups, and lower to about five feet six inches for sitting figures and children. The general arrangement may be in the form of a curve or L shape, one lamp being apposite the centre of the background and about seven feet away, another apposite the edge of the background and a little nearer to it, while two of the others are placed between these and two to serve as a side-light or for Rembrandt effects. Each lamp should be on a separate switch, so that only as many as may be necessary are burning at one time. It is very necessary that the exact voltage, not a nominal one, should be given when ordering lamps. Inquiry should be made at the local power station, for a very slight drop in voltage means but little loes of light visually, bat a gnat deal as regards the actinic value. In meet cases where length of exposure has been complained of I have found this to be die cause. In districts where variations of current are common it would be well to use slightly lower voltage lamps than the nominal local voltage calls for, and to have the adjustable resistance supplied for these lamps and regulate the current as needed.


Tuesday, June 3, 2008

Economy of Chemical

           When we compare the present prices of nearly all chemicals with those ruling before the war we find that the increase in the year's expenditure in this direction is a serious matter, and as it is a matter of percentages as serious for the small user as for the large one, whether the expenditure be five pounds or five hundred, it is important that full value be obtained for it, and this can only be done by keeping a watchful eye upon every stage of the work.
           Very often waste begins even before solutions are made up. This is usually due to the want of proper receptacles for the stock when it is delivered. Quite often chemicals, such as sulphite and carbonate of soda, alum, and even ferricyanide are purchased in paper packages of twenty-eight pounds or less, and taken into use at once without putting into proper jars, the parcels being laid upon any convenient shelf exposed to the air and dust, besides often being scattered upon the shelf or floor. It certainly should not be necessary to allude to such a state of things, but it undoubtedly exists in many places, and should be stopped without delay. Next to this is the practice of guessing at quantities when mixing solutions, for in this way a loss of 10 to 20 per cent, may easily occur, especially in the heavier kinds we have mentioned. It is not necessary to weigh most chemicals carefully as a system of dry measurement is usually sufficiently accurate, but it is desirable to keep in each jar or cask a measure which will hold what may be called the unit quantity, so that any boy or girl may be entrusted to make up the usual bulk of solution without supervision. Nearly everybody makes up certain quantities of solution at a time. To take the case, say, of pyro developer, the jars holding sulphite, carbonate, and metabisulphite should each contain a vessel such as a jam-pot or one of the cardboard canisters now commonly used, which when filled to the brim and struck off level will hold exactly the quantity required for a Winchester of solution. The card canisters are convenient, as they may be cut down to the right depth with a penknife. The pyro itself is usually supplied in ounce bottles, so that no measurement is needed, but if purchased in bulk in the crystal form it should also be measured, or, if in the old resublimed state, carefully weighed. This should be done not only as a means to economy but al-o as tending to uniformity of result. The same system should be applied to other solutions, such as amidol, hydroquinone, and such things as reducers and intensifies, the only exception being when the stock solutions are saturated ones. With amidol developer the practice of making a stock solution of sulphite and adding the dry amidol as needed is an especially wasteful one, as there is always the possibility of using more than is needed, and. moreover, neither the mixed developer nor the sulphite solution keep in working order so long. The better way is to make a fair quantity of solution at once with the addition of meta-bisulphite as a preservative. A good formula is two ounces of sulphite of soda and a drachm of metabisulphite dissolved in twenty ounces of water to which is added a quarter of an ounce of amidol. This is diluted with an equal bulk of water for use, and will keep in good order for a week or more. It is frequently the practice to throw away amidol solution which has been little used, and although we do not advocate overworking it, it has been found quite practicable to keep used developer over from day to day, adding fresh a- needed. In one studio the amidol was kept in a jug after use, and only thrown away when the excess of bromide rendered it necessary. The prints produced by this procedure were as good as most that we have seen. In this case we may say that no bromide was used in making the original solution.
           A very common cause of waste is to be found in a hurried, sloppy method of working, by which much solution is carried away upon the prints, e.g., when removing enlargements from the fixing bath. If a print is lifted quickly out of the hypo quite an appreciable quantity is carried into the first washing water, and at the and of the day's work the bulk is seriously reduced. With hypo at six shillings a hundredweight this is a small matter; at sixty shillings it is not. Even more wasteful is this practice in sulphide toning. Some printers’ wasteful quite half of the costly bleacher in this way.
           Those who still work the gelatino-chloride or P.O.P. printing will find that the Eastman system of allowing a definite quantity of gold to a certain number of prints a very economical way of working, practically all the gold being used. For the benefit of those unacquainted with the plan we may explain that if a grain of gold be allotted to each dozen cabinets for a purple tone, by diluting the solution a larger number may be toned to brown or still more to a reddish colour, all the prints being put in at once and allowed to remain, until the bath is exhausted. This not only saves gold, but ensures even toning.
           Using an excess of solution for any purpose is so obviously wasteful that it hardly needs mentioning, yet it is frequently done. We have often seen three times the necessary quantity of ferricyanide reducer made up for cleaning a few bromide prints, while pyro developer is often used in a too lavish manner, especially when concentrated stock solutions are used. It is false economy to stint the developer, and many poor negatives are the result, but many assistants habitually use twice as much or even more than is really necessary.
           Although not strictly within our subject, the waste of bromide paper through careless cutting or tearing deserves a word. One often sees prints with a margin nearly half the area of the finished print. This is not only wasteful of paper, but of all the solutions used. Odd-shaped enlargements such as eleven by seven upon twelve by ten paper run away with a strip which if trimmed off before exposure would serve for tests or even for small prints. All these little things mount up in a year, and even if the exact amount saved cannot be calculated the profits will appear appreciably better. Wartime orders are at an end now, and it is well to bear in mind the old proverb that a penny saved is a penny earned. There is another which says penny wise and pound foolish. The wise man will steer between these extremes.

EX CATHEDRA: Stamps and Box Nos, Iodine-Cyanide, "Close Up" Pictures, Print Washing.

Stamps and Box Nos.

           What is alleged by a correspondent to be a grievance amongst assistants who apply for situations advertised over a box number is the non- reply to such applications when a stamped and addressed envelope is enclosed for the purpose. It has been suggested more than once that the publishers of the “B.J.” should devise some plan by which the grievance should be removed. Out of curiosity we should like to know of a plan which would achieve this end, for we can conceive of none but that which applicants have in their own hands, viz., to refrain from sending stamps for this purpose. In this matter it is necessary for an applicant to put himself in the position of an advertiser who receives a score or more replies to an announcement. Naturally the applications from those who seem suitable are replied to, but the general commercial practice is to leave the others unanswered. That being so, the enclosure of a stamped and addressed envelope imposes on the advertiser an obligation which he has not invited, and which, therefore, he may disregard. No doubt there are some employers who will reply to every application from motives of old-fashioned courtesy or from a wish to obtain a reputation for consideration, but the majority will never think of it. And the assistant may be asked to think that the enclosure of payment for reply will not in any degree improve the chances of his engagement. It is inconceivable that any business man will be influenced in his choice of an assistant by the fact that he is saved the cost of three-halfpence in communicating with him. On the other hand, he may very easily interpret the fact as evidence of nervousness or want of confidence on the part of the applicant.


           For some reason or other the compounding of this reducer of prints and negatives is the cause of more queries to us than is any similar preparation. The failures of which our correspondents complain may be roughly divided into two classes: (1) Making the iodine solution, and (2) ensuring activity of the mixture. Failure under No. 1 can be infallibly avoided by working in a certain way; that of No. 2 arises from the varying strengths of commercial cyanide, and calls for adjustment by trial of the proportions of the two solutions. As regards the iodine, the secret of causing it to dissolve completely and quickly in the iodide is to add only just enough water to dissolve the crystals of the latter scarcely more than required to cover them, for they are very soluble and then to stir in the iodine flakes. These will dissolve almost instantaneously, and will remain in solution on diluting with water to the required volume. But if this latter is used for dissolving the iodide, the iodine is soluble in it only by the exercise of an enormous amount of shaking or stirring, and usually cannot all be got to dissolve. In regard to the second point, inactivity in reducing power of mixture of iodine and cyanide solutions is very often due to insufficient cyanide. The latter may be largely contaminated with cyanate which is inert in forming the reducer. Therefore, if the solution does not act as it
should further cyanide solution should be added; and if that fails, the solid cyanide is probably of too impure a quality and a brand of guaranteed 80 or 90 per cent should be bought. The reducer, of course, is not active unless containing a proper amount of iodine, which is used up in tin- treatment of prints, but, given that due proportion, want of energy in bleaching the silver deposit is occasioned by insufficient real cyanide.

"Close Up" Pictures.

           A little point which we have noted in several excellent cinematograph films is the very flat lighting in the large pictures of the leading actors and actresses. As most of our readers are aware, these are interpolated between the scenes in order to show more clearly the emotions which the character is supposed to be displaying. The effect is somewhat marred when the face is a ghastly white and the make up of the eyes and lips the only visible things. That this is unavoidable cannot be urged, for we have seen some such productions which would vie with finished portrait work, and it would seem that the defect is only due to a neglect to arrange for the special lighting which is necessary for a single face. On looking at good examples of this work we have wished that it were possible to make portraits of private sitters in the same way. There would be, we are sure, a good market for them if they could be produced at a reasonable rate, and a satisfactory method of showing them devised. The ordinary projection apparatus is bulky and inconvenient, and cannot be readily used in daylight. Probably many of our readers remember the original Edison apparatus in which the films were inspected by means of an apparatus somewhat resembling a magazine stereoscope, the illumination being by means of an ordinary incandescent electric bulb. In this apparatus the film was in the form of an endless band, so that the episode could be repeated as often as possible without rewinding. Some time ago we saw a cylindrical film on which the pictures were arranged in a spiral somewhat like a phonograph cylinder. If this idea could be carried out in a satisfactory way it should become popular. There have been attempts to make home cinematographs working with glass plate, but these are too fragile and cumbersome to appeal to the non-technical public.

Print Washing.

           As a rule it is some little time before the presence of hypo in an imperfectly washed print becomes manifest, but sooner or later it makes trouble for the careless producer. With ordinary black bromide or P.O. P. it may be months, even years, before a general yellowing of the image or uneven patches begin to appear, but with sepia-toned bromides retribution is swift, for deterioration sets in before the work is finished, and sometimes the cause is not suspected, the paper, the bleaching solution, and even the sulphide bath being blamed, while the fault is due to improper washing. The great fact to be remembered is that Farmer's reducer is composed of ferricyanide and hypo, and that no matter in what form or for what purpose a solution containing these two chemicals is applied to a print the effect will be the same. We all know that when a print has been locally reduced the tone of the reduced part will be different from that of the remainder; sometimes only slightly and at others very noticeably. Now a very small trace of hypo in a print is sufficient to react with the ferricyanide in the bleacher, and to start reduction of the image sometimes evenly and sometimes in patches or streaks. We have seen a batch of excellent prints which should have given excellent tones turn out a wretched ginger colour from this cause alone, and not only have the badly washed prints been affected, but properly washed ones have also been spoiled by the hypo conveyed into the bleacher by the former. Unless carefully watched many printers will trust to throwing prints into a large dish or sink and allowing a tap to run upon them, and if that tap runs for an hour they will say that the prints Lave been washed for that length of time. Failing a perfect mechanical washer there is no safe method of freeing prints from hypo except by hand washing, that is transferring the prints singly from one dish of water to another. Even as few as six changes of five minutes each in this way, provided that an ample quantity of water is used, will render prints safe for toning, and secure black ones from fading. There are two well-known tests for the presence of hypo, permanganate of potash and iodide of starch, and it would be well for anyone who is getting bad colours from apparently good black prints to apply one or the other. We know of one great firm which tests every batch of prints, bromide or gaslight, with permanganate, and the results are conspicuous for their good tone.

The Gum Bichromate Process With A New Colloid.

[The following is the extended account, as published in the Journal of the Royal Photographic Society, of the experiments made by H. S. Starnes and the subject of the paper read by him some time ago before the Society, Mr. Starnes, it will be seen, employs, instead of gum arabic, gum Senegal and prepares this latter gum upon the paper in an acid condition. In this respect the process bears some resemblance to that of Mr. Nelson K. Cherrill published some years ago in which arabinic acid of gum arabic was previously separated by treatment o! the gum with acid. EDS., " B.J."]

           He considered that the bichromate printing process was an ideal one, for the following reasons:-1st. There is an almost unlimited range of colours; 2nd, if suitable pigments are used there is no doubt about their permanence; 3rd, there are no such things as double tones; and, 4th, there can be the same surface of paper as in an engraving. On the other hand, the gum-bichromate process will not give the same fineness of grain that a silver print does, but except for small portraits the grain will probably be fine enough.
           In all types of bichromate printing the principal difficulty is in removing only the soluble parts not acted upon by light. In Sir Joseph Swan's original carbon process the film of gelatine and pigment was transferred to a temporary support and the soluble matter was washed away from the back quite satisfactorily, but it required double transfer and warm water. Then came the Artigue process, which did away with the double transfer, but had to be developed with wet sawdust, and frequently the lighter detail would not stand the friction, and was washed away.
           Shortly after the advent of the Artigue process the lecturer worked out a process which Sir Joseph Swan told him was the first real advance in bichromate printing since the original patent. The exposed print was soaked in water for a minute or two and laid face upward on a piece of glass, a piece of dry blotting paper was laid over it, and a soft clothes brush was brushed over the back. The soluble part of the film was taken up by the blotting paper, and the insoluble portions forming the image, especially the lighter tints, were pressed down into closer contact with the paper support. Sir William Abney had suggested to him that possibly that method of development might give a suitable grain for process work. The lecturer had no experience of process work, but was pleased to pass on the suggestion to anyone who could make use of it. Although the blotting paper preserved the light detail, still the lecturer had the same trouble as those who tried to revive Pouncey's method of printing very deeply and removing the soluble portions with a wet brash - there was no dependence on the condition and solubility of the gum arabic.
           When the bichromate printer was an artist he could remove what he liked and leave what he pleased, but the ordinary worker lacking that ability was likely to give the process up in despair. He felt, however, that there was something in the process if he could get a more suitable colloid than gum arabic. He had gradually worked his formula down to the point that to get the best results the paper must be coated so thinly that one minim of the combined mixture of water, gum, pigment, and bichromate must cover four square inches of surface. The brush, the sawdust, and the nozzle of the garden hose were all too brutal in removing the pigment, and blotting paper was too expensive. After experiments, he came to the conclusion that a straight tube about 3 in. in length, with a bore about the same as in a tobacco pipe, and fitted to the domestic water tap, answered well, as the force of the abrasion could be controlled by varying the supply of water. When he wished to concentrate the action of the water upon small areas he used smaller nozzles, which fitted over the first one. There was then pleasure and interest in working on every square inch of the picture.
           In searching for a suitable paper he discarded most of those used by the bichromate printers for one reason or another. Cartridge paper and the cheaper drawing papers allowed the coating to sink in unequally. Whatman's paper, in addition to being expensive, allowed the pigment to sink in to some extent, which, although just what the water-colour painter wanted to prevent washing up, was not the property wanted when using the bichromated solution. Some pre-war note-papers were better, and he found a paper used in collotype printing which was at first excellent, but later samples were of inferior quality. He was now using a foreign paper obtained from Spicer Bros., and would send a sample to anyone who sent a stamped directed envelope to him at King Henry's Road, Lewes.
           Some of the pigments he had tried contained a proportion of dye, which stained the paper. Messrs. Brooke, Simpson, and Spiller had made him a stock of suitable pigments. He used a carbon black modified with blues, browns, or reds, as required.
           He found that refined sodium bichromate worked better than the other bichromates, and got a good sample from J. J. Griffin, Ltd. The stock he has was made in Germany, but he hoped that English firms would now make it.
           Nine-tenths of the trouble in bichromate printing arose from the varying characteristics and conditions of the colloids used. The conditions in which gum arabic is collected and stored make it hope less for the purpose. He, found that he might get passable results with it from one negative, yet could do nothing at all when working from another, even though the paper in use was cut from the same coated sheet. The problem had bothered him for years.
           He had to make a rather startling statement, which wag that wider certain conditions the action of light makes a bichromated colloid soluble instead of insoluble. This would explain why the readings of the actinometer were not always reliable, and why one f negative would give better results than another. The action seemed to be as follows: - When the bichromate is added to the colloid it renders the latter more or less insoluble at once. On exposure to light it slowly becomes quite soluble, and after it has reached that stage it begins to get insoluble as under normal conditions. Different samples of gum work differently with regard to the length of time for those two actions to take place. Freshly-made solutions are more prone to act so than solutions that have been kept for some time.
           At first he thought that different samples differed as slow and rapid plates do; then he found that there must be two actions going on simultaneously, because the parts of the print under the densest parts of the negative were darker than under the half-tones, while under the lightest (or clear glass) parts of the negative the prints seemed to print normally, but not with the density that the amount of pigment ought to have given; so evidently some of the gum was not holding the pigment on to the paper. One day he got a print that had black sky. The trees in the distance looked as though they were covered with snow, and the shadows, which ought to have been the darkest parts of the print, were simply Half tones. That print gave him a clue to the mystery. He showed a print which at the first stage of exposure was a negative from a negative; another showed the two actions going on simultaneously during the same exposure to tight, and another which had first gradually been rendered soluble until, by the time it was soluble under the densest part of the negative, the other parts had again become insoluble in their proper sequence, and it was becoming a practically normal print. He was inclined to think that the first stage was purely a physical one, that the bichromate had bound up the colloid too tightly, and that the first thing the light had to do was to unfasten the straps, if he might use that phrase.
           About thirty years ago he 1had written an article for THE BRITISH JOURNAL OF PHOTOGRAPHY, in which be gave a somewhat similar explanation of the action of light on a dry plate.
           He had searched through many books on bichromate printing to see if a double light action of this kind had bam observed, bat no one seemed to nave noted the phenomenon The matter was one of considerable importance, as it accounted for a very common fault in prints. It was often found that bichromate prints break down in the rendering of the lightest tints, because under the densest part of the negative the film, instead of being made insoluble for the lightest tints of the print, would be undergoing just the reverie action, and would be made even more soluble, and would wash away more easily, so that it appeared as though the print had been under exposed. The lecturer had made many experiments in the hope of finding some method of keeping the film of bichromated pigment soluble, so that the light action should be restricted to its legitimate function of insolubilising it according to the gradation of the negative. It was not until be had worked out the following formula that he began to see daylight

           A. – Sodium bichromate ……………………………… 1 oz.
                  Water ……………………………………………… 2 oz.
           B. – Alum, saturated solution ………………………… 4 oz.
                  Hydrochloric acid …………………………… 2 drams.

           Take one pert of A to three parts of B. If with a certain sample of gum this makes the film too soluble, then reduce the amount of B.
           Having found gum arabic to be unsuitable, he had tried a number of other colloid, and finally hit upon gum senegal. As an adhesive it was probably not satisfactory, but for printing purposes it works much better than gum arabic, being softer, less brittle, and more under control. It contains 81 per cent, of arabin, as against 70 percent, in gum arabic.
           To make the gun solution a quantity of it is suspended in a bag or ware cage is pint water, and as it dissolves more is added until one fluid once weights 9 drachms. To measure the pigment a salt spoon is used which will hold just 20 minims of water, and four spoonfuls of the pigment (strike measure) are taken the precise quantity nay vary according to the covering power of the colour, and is ground up with 1 drachm of methylated spirit. This is added to 1*(1/2) drachms of water, mixed thoroughly, and placed in a test-tube to settle for a few minutes. One and a-half drachms of the gum solution is taken, and to it is added about three-fourths of the pigment solution, care being taken not to shake up the coarse sediment at the bottom of the test-tube, and the whole is mixed well together. The pigment that had settled at the bottom of the test tube should be re-ground and added to the mixture. To that is added 1 drachm of the sensitizing solution, consisting of 15 minims of solution A and 45 minims of solution B. In winter, solution A may be increased to 20 minims. The quantities given will coat about twelve pieces of paper 10 in. x 8 in.
           To coat the paper it should be fastened by one corner to a sheet of glass or zinc, supported if necessary on a wooden board, which in turn rests upon a penny laid on the table, so that the device may be revolved easily in any direction. A spoonful (20 minims) of the mixture is poured along the length of the paper from left to right at about 1/2 in. from the edge. The colour should be spread evenly over the paper with a 2-in. varnish brush with light strokes, turning the turntable as required, but always keeping the brush flatwise on the paper. If the brush is turned edgewise streaks will appear. With a little practice it will be found quite easy to coat 4 square inches of paper with 1 minim of the mixture.
           The coated paper should be placed about 2 ft. from a fire or gas stove, and by the time the second piece of paper is coated the first ill be dry. After use the brush should be cleansed with water and a nail-brush and dried thoroughly before it is again used.
           The exposure is about one-eighth of that required by P.O. P., and is gauged by an actinometer.
           For development the print is soaked in water for abort a minute and then flooded with solution B (acid alum) 1 drachm, water 2 oz. If the exposure has been correct the colour in the high lights will be sera to float away in a few seconds. The print is then put on a glass easel in the sink and development completed with the aid of the rubber tube and nozzle device previously described. More control over the print is obtained by giving a longer exposure and by using the acid alum solution in a stronger condition.

Some Notes On Print-Meters

           Of the many forms of print-meters, or actinometers, the type dependent upon miniature negatives of graduated density is preferred by some, as no matching of tint is required, and for occasional work with only a few frames exposed it certainly is convenient. On the other hand, the most accurate of all probably is the "single-tint" tint-matching type, almost essential when many frames have to be kept going and taken in and out during the day's work, but it requires constant inspection, and if one tint is over-done accidentally only a rough estimate is possible to compensate for the over-printing. Single-tint meters, such as Johnson's, supplied by the Autotype Company, are provided with a roll of P.O.P., which under varying atmospheric conditions does not always make a good match: with the surrounding tint, the yellow glass above necessarily being of insufficient depth to remove colour contrast. Greater accuracy in reading is secured by not attempting to effect a colour match, but to work in the following way: If the nearest edge of the rectangular aperture is viewed obliquely from a fair distance with the eyes partially closed, it will initially stand out lighter than the darkening silver paper beyond it, and at a certain stage will merge into the tint and be lost, which point is taken as "one tint." Tests have shown that this method largely eliminates the personal equation, one printer, practically speaking, registering the same number of tints as another, whereas in the case of colour matching by gazing directly downwards on the meter wide differences in the estimation of what constitutes a tint have been found. A variant of "Johnson's" is the circular meter with disc refills: it is cheaper, but for professional use the former is the better. In some cases celluloid is used to protect the tint, but it is an indifferent substitute.
           To insure accuracy with thin or medium negatives, the meter should register three or four tints during the printing, accuracy being of more importance when printing platinotype or palladiotype by meter than with the carbon process, which has greater latitude in exposure, or, rather, errors in exposure are more readily corrected in development. But a quick-printing single-tint meter is a decided nuisance when dense negatives are being dealt with, and in such a case a fixed-out lantern plate dyed yellow with bound-on cover-glass can be placed over the meter and will be found very useful to slow down its indications. As a matter of curiosity, it may be mentioned that the extreme variation in the rate of contact printing met with in one trade printing concern ranged from three minutes to twenty hours, the negatives - being exposed to the same
Some Notes On Print-Meters Fig.1

mercury light, and each negative affording good prints. The perpetrator of the twenty-hour gem had "faithfully promised his customer a dozen prints at the end of the week," as is usual in such cases.
           Other forms of print-meters based on tint-matching are illustrated by "Sawyer's" and the "Akuret," the sensitive paper being exposed under translucent tints of different densities. They possess an advantage over the single-tint type, as no movement of the paper is required whilst the negatives are being printed, but their scope is not so wide. The familiar Wynne's meter, dependent upon numbers successively printing out, is a favourite with many, though others experience a difficulty in deciding whether any particular number hat, or has not, appeared Finally, the type first alluded to is the device of Mr. H .J Burton, on the lines of which the making of an efficient home-made article is to be described.
           Not a few have attempted to make print-meters of the graduated miniature negative order, by copying a photograph in the camera, or by exposing by contact a dry-plate behind a positive, in either case successively on different parts of the plate, with an increased time of exposure for each small negative, but this method is very uncertain, and the results are usually far from satisfactory for fairly obvious reasons. It is also obvious, when mentioned, that to attempt to design a meter capable of indicating exposures from thin negatives up to those of extreme density, either means an undesirable multiplication of the tin; guide negatives, or an equally undesirable abruptness in the translation from one to another. For unnaturally dense negatives, one or more pieces of ground-glass placed over the meter will meet the case.
           Fig. 1 represents a quarter-plate negative of nine prints stuck on white cardboard, which are reduced by copying in the camera to a little less than 2*(1/2) inches high over all, in position shown on the plate. The prints should be of the same subject, preferably a portrait rather large on the plate, and whilst it is an advantage that the set be uniformly lit, even illumination is not essential. Over-exposure is to be avoided as bright, but fast printing negatives with almost clear glass shadows are the moat suitable. If the ground prints through it is blocked out.
           Assuming the figure to represent the glass side of the plate, and the negatives to read from left to right in the usual way, the graduation in printing rate is effected by covering No. 2 with one layer of celluloid, about the thickness of that used for cut films, No. 3 with two layers, and so on. Fig. 2 shows the first sheet of celluloid applied with extremities extending beyond the miniature negatives,

Some Notes On Print-Meters Fig.2

but clear of the edges of the glass; on the right about 1*(1/3)th inch, on the other three sides more space is available. The next sheet has space 2 cut away, and is stuck down at each end with a touch of celluloid varnish, the procedure being continued mutatis mutandis until No. 9 is covered with eight thicknesses.
           When the first test of the meter is made everything may appear right, the lower numbers being nicely graded, and on printing further the faint images of the highest numbers apparently the same. But here exists an unsuspected trap, for on printing, say, No. 5, to the "pretty" stage, No. 6 may now be found to be almost indistinguishable in depth, and therefore require further ho. ding back, together with the numbers following it.
           Accordingly, the only safe plan is to test each number right through the series at its "pretty" stage against the next less printed one. Some pieces of stripped thin roll- film may be found of service when only a very slight holding back is demanded. The celluloid covering is then edged all round with cardboard slips stuck down with seccotine, and a thin cover-glass bound on. If the lower numbers print too quickly for the negatives in use, the cover-glass may be of ground-glass. A three-quarter-view quarter-plate printing-frame holds the finished article; white wood frames are sold sufficiently deep to take it. A packet of 3*(1/2) x 2*(1/2) ordinary gelatine P.O. P. provides the meter paper, and will keep for years if stored in an airtight tin with some dry calcium chloride. Self-toning papers are not so good for the purpose. When the number indicating the correct exposure is found by trial, naturally only a narrow strip of paper need be utilized afterwards.
           In the model constructed, which has worked well, for identical depths of printing the last number requires about six times the exposures of the first, a range sufficient to satisfy most requirements. This ratio, of course, only holds good for the particular thickness of celluloid employed. Comparative values might be given each negative if a single-tint meter is at hand, or improvised, by registering the number of tints necessary to bring each negative in turn to the pretty stage.