Wednesday, August 13, 2008

Soft Effects In Enlarging.

[The facility and economy making portrait prints by enlargement are advantages of a system which is growing in favour, and which has a further claim to the notice of photographers namely, the opportunity which it affords of producing a portrait of diffused definition from a negative of the ordinary character. This is a point which receives special emphasis in some notes on enlarging which we reprint below from "Camera Craft." Their author, Mr. J. Walter Doubleday, describes the particular form of device which he employs in breaking up to a pleasant degree the definition in the negative. EDS. B.J.]
Bromide enlarging is steadily growing in favour, even more rapidly than would be the case were only those workers taking it up who are changing from the formerly popular view camera sizes to the present more convenient small type of cameras. I know a number of professionals who are making all their portrait work through the enlarging lantern, not alone for the purpose of securing larger prints than the negatives they care to make, but for the control and speed that the process permits. They have, of course, some- what modified their apparatus, by eliminating such parts as serve mainly to give a large range as to size, and by adding other fitments that increase rapidity of production.
I have mentioned thin, not as an introduction to the subject of apparatus, which I shall avoid, but as a means of suggesting the recognized simplicity and advantage of making prints in this way. Enlarging apparatus is of such varied form' depending upon the light available, the requirements of the user, and to some extent the pane M well, that space does not permit me to do the subject justice if I am to record a few of the things I have learned about the actual production of bromide enlargements, things common to the work, irrespective of the form of apparatus used. Enlarging on bromide paper is quite simple, the apparatus required is not complicated, and the results have the highest endorsement of our best professionals and our leading exhibitors.
The negative best suited for enlarging is one that is soft, yet brilliant. But it must be brilliant. The kind of softness that "results from full development of an over-exposed plate or film, soft- ness combined with thickness, will not give a good enlargement. Slight fog or veiling of the image is also detrimental, and one must not assume that because such a negative will make a good contact print it should produce a good enlargement. This is a common mistake. The reason for the difference lies in the different action of the light. When the light is projected through such a negative in enlarging, there is a scattering of light from all portions is of the silver deposit, and when there is even a slight deposit where it should not be, as in the case of fog or thickness, poor results must follow. In contact printing there is not this scattering of light and not the same ill effect produced. One should strive for brilliancy with softness, and the use of a lens shade, particularly in the case of our rather short hooded and large aperture instigates, will do much in that direction. A safe dark-room light and a clean working developer will also heap.
The strength of the light used in making the enlargements also has much to do with the quality of the negative best suited to the n' requirements. Or rather, one can, by selecting a certain form of light, accommodate the process to negatives of quite different quality. The thin, fully exposed, yet under-developed negatives that some professionals affect, can be made to produce good enlargements only by using a rather weak tight, such as an oil burner or gas jet produces, strong, contrast} - negatives require a strong light; and negatives carrying much retouching are beat enlarged with well diffused daylight or a strong artificial light, like the arc, with ground glass between it and the condenser. The use of a soft-focus lens is also moat advisable in such cases.
The truth of the matter is, she best plan is to find oat, by experience, just what kind of negative is best suited to one's individual equipment, and then make negatives as near that standard as possible It is quite obvious that only a worker with an extensive output to produce could equip himself with sporrans employing varying strengths of light as suggested above. A compromise, to grades of paper offered; the range, since the introduction of the on-called chloride papers, with a speed some where between that of regular bromide and the gaslight papers, ranking this power of selection a valuable asset.
I suppose I should attempt to go into same detail on this latter point, bat while the mage is so wide, it is yet somewhat variable in different localities, and little would be achieved. At leant, little compared to what the individual worker can best find out for himself by a very few experiments based upon the quality of the negative in hand and the maker's description of the various papers available in his case.
The exposure is the most troublesome factor of the entire proems, but this has lost its terror to a great extent since the advent of developing papers. In the days of printing out papers, with their visible image to serve as a guide, the correct timing of a bromide enlargement screed to be much more of an achievement than was actually the ones The best plan, in my animation, is to take such negative, as made, and give it Bomber that expresses something in the form of a ratio, something that will give an easily handled factor from which to figure the exposure in enlarging to any size. This can be done by making n correctly timed contact print on developing paper and noting the time, the time serving as the factor number. It is, of course, quite necessary that these factor numbers most all be determined under exactly the same conditions. A standard brand of paper must be used, one having little or no variation in speed, and the light and distance used in malting the print mutt also be uniform.
If all one's negatives bear on their edge the number of second’s exposure required to produce a correctly timed print on, say. Regular Velox, exposed to a cluster of four thirty-two candlepower Mazda lamps at a distance of sixteen inches, little difficulty would be experienced in determining the correct exposure for any one of them for any size of enlargement, after a few experiments had been made. There would be a fixed relationship between these factor numbers and the number of seconds required for enlarging to different sixes, sad the relationship could be easily determined by an experiment or two. One might find that the exposure required for a two time allurement, or enlargement to a certain commonly used size, was one and one-half times the exposure number established by the making of the contact print on developing paper. He then has but to read off the umber on the margin of one of his negatives, multiply it by one and one-half, and he has the correct exposure for an enlargement of the designated size, providing that lens stop, strength of light, and grade of paper remain constant. If any of these are varied, proper allowance is easily matte. A larger for smaller stop decreases or increases exposure in the same ratio as in regular work; the difference in the speed of the papers used is determined by experiment, sod of coarse one's light is practicably constant except daylight is employed In this letter case an inclinometer can be used to determine the variation from the normal, if any. Practically all of the annuals carry a table giving the relative exposures for different degrees of enlargement, and 1 hardly need to occupy spare with a repetition of one of them here. Soft effects in enlargements are sometimes quite desirable, and we know of several forms that are making quite an enviable reputation on their bromide enlarging by using the legs pronounced effect secured with the soft-focus lens employed for all their work. But all obtainable sharpness is often desirable, and we must be prepared to secure this last before we can regulate the amount of diffusion to our liking. Some workers find it very difficult to secure a satisfactory degree of sharpness, even from a negative that is undeniably sharp, and we will therefore take up a few of the possible causes for their difficulty. First, there is often an unsuspected lack of accordance between the chemical and the visual image projected by some lights, particularly the enclosed are. Where this is the case, the variation must be determined by trial and allowance made for it in focusing. While the difference varies slightly with the size of enlargement, only the general difference need be considered and made up except where an unusually large stop is being employed. Where a condenser is used, failure to adjust the position of the light for different sires of enlargement will also cause lack of sharpness. The light should be so placed it is lathe focus of the condenser for revs of light from the caser; in other words, the cone of light, after passing through the is, should come to a point small enough to pass through the stop of the lens. The distance of the light back of the condenser for different positions of the lens which last means different size of enlargement, can be determined by focusing through a negative upon the easel for the desired size, then removing the negative and observing the distribution of the illumination as the position of the light is changed. Another frequently unsuspected causal of unhappiness is the use of the rising and falling, or the cross front, in bringing the image in the desired position on the easel. The centre of the lens, of the negative, the condensers and the light, should al be in a line and not oat of centre with each other. It is also obvious that the lens carrying front of the camera or enlarging lantern must be in a plane parallel with that of the other elements, or this cent ring of the lens cannot be achieved. Dirt on the lens or vibration of some part of the apparatus during exposure is detrimental, and the bromide paper should lie perfectly flat against so as to receive the image in the plane of critical sharpness.
Soft effects are, as I have said, frequently the most desirable, both for pictorial and other reasons. A hard, black mass with a harp outline, is much more objectionable than one with a softer edging, as any landscape worker can testify, if he has given the matter any thought. In portraiture, the breaking up of all suggestion of hard lines is almost sure to result in improvement. With the soft-focus lenses some moat planting results are secured, and it might be wail to point out that different makes of these lenses give somewhat different result*. The worker will, if buying a lens of this type, do well to try more than one and decide for himself which beet suite his requirements. Bolting silk, stretched on a frame and interposed about three or four inches in front of the paper on the easel daring all or a part of the exposure, is a quite common method of securing a breaking up of the image. The distance from the paper regulates the amount of breaking up achieved, and this distance again depends upon the distance of the paper from the lens. A more delicate softening is secured by using two thicknesses of chiffon to face a cap placed on the lens.
In my own practice the mount on the lens is fitted with a wire frame in which a movable slide is held close against the front hood, This slide is a piece of cigar-box wood about three times as long as it is wide, the width being sufficient to well cover the front of the lane. The centre of this slide is left solid, but a circular opening, large enough to permit free passage of light to the lane, is cut is each end. One of these openings is covered with two thicknesses of the chiffon material and the other with a piece of yellow glass, both let into the wood so as to be flush with the surface. With the centre of this elide in front of the lens, the cap is on; with the yellow screen in positioning, the paper on the easel is in safe light while being adjusted in position; and, with the chiffon section in front of the lens, my soft enlargements are exposed. One could make the slide longer and include an unscreened opening, but in practice I found that lifting the slide out of the wire frame was less liable to shake the lens than trying to move it along in the proper position.
Even more important control of the results ill enlarging can be secured by shading different portions of the image during exposure; or rattier, during a portion of the exposure. A piece of cardboard, an old mount, preferably of a dark colour and roughly torn to the desired outline, serves at the shading medium and is to be interposed between the lens and the easel, or at least, some little distance from the paper. This .should is kept in motion during the time it is being used, in order to further avoid a too sharp outline, the length of time it is interposed being proportioned to the entire exposure in accordance with the amount of holding back it is thought desirable. It is obvious that where the part to be held back comes fully within the boundaries of negative, this plan will not avail. One can then resort to a piece of the card torn roughly to the desired shape and fastened to the end of a piece of stout were; an ordinary lady's hatpin answering admirably. Another plat is to attach the .shading piece to the centre of a piece of glass and use this last as a support to enable it to be gently moved about so as to shade the part intended. Variations of these suggestions will suggest themselves to the worker and enable him quite rapidly to acquire the knack of exercising most beneficial control of nearly all his enlarging work. In fact, it will be found that practically every negative from which an enlargement is required is amenable to treatment of some kind along this line.
I might point out that availing one self of these possibilities makes it advisable to increase somewhat the exposure time, and this last is best done by some other means than decreasing the size of the stop. The most practical method is to introduce one or more sheets of ground glass in front of the light employed. Using a slower paper may not give one just the effect desired different speeds of paper printing differently, and decreasing the stop affects the illumination where a condenser is used and sometimes introduces granularity in other cases, even resulting in an enlarged image of the ground glass diffuser behind the negative being recorded upon the enlargement


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