Amateur Photographer & Cinematographer (1936)

November 4th, 1936 fH[ AMATEUR PHOTOGRAPHER fa 6 CINEMATOGRAPHER a hoosing an Enlarger While the choice is less wide than is the case with cameras many photographers are puzzled at the variety of enlarging apparatus offered. The matter of choice is dealt with in this article, with regard to individual requirements. IN these days, when most photograpliers make small negatives, enlarging apparatus of some kind is an essential item of equipment. At the present time there is a great variety of such apparatus available, and, as with tlie choice of a camera, the photographer of limited ex]-)erience needs a little help in selecting the instrument best suited to his needs. There are two main types into which present-day enlargers may be divided. There is the high-speed vertical en¬ larger, the more expensive models of which are fitted with an automatic focussing arrangement and a largeaperture lens. The projector-head slides up and down a vertical pillar, the image being projected downwards on to a large board. This usually carries a paperholder of some convenient kind, and serves, in addition, as the base upon which the whole enlarger stands. The horizontal enlarger is built rather like the optical lantern used for the projection of lantern slides. The place of the screen is taken by an easel upon which the paper is pinned. This easel is in most cases structurally separated from the enlarger itself, the two being brought close together for making small prints, and separated more widely for big enlargements. This is a general description of the two types of enlarger, but it will be understood that there are minor differences between different models of the same type. For example, some models rely on a condenser for even illumination of the negative, while others dispense with this and secure the same end by means of a diffuser. In some instruments the two systems are combined, a collecting lens being used in conjunction with an opal bulb or other source of diffused light. Vertical Enlargers : Advantages and Limitations. The photographer may find that the vertical enlarger has points of special advantage in his particular case. They are gener^illy more compact than the horizonta^l tvpe, and may be operated in a rather smaller space, an advantage when dark-room accom¬ modation is limited. The fact that many of these enlargers are of the automatic focussing type is also an advantage to those photographers whose vision is not of the best, and who find a difficulty in focussing. The setting of a scale determines the size of the enlargement, sharp focus being automatically maintained no matter how the size ma^; be varied. These enlargers are limited with regard to the largest print that may be made, although in most cases this is in the region of 1 5 x 12 inches, a size sufficient for most purposes. Fitted with a large-aperture anastigmat lens, ex¬ posures are very short, making it possible to use the slower or chloro-bromide papers for the purpose of enlarging. Horizontal Enlargers. While the vertical enlarger repre¬ sents the latest development in en¬ larger design, there are still many photographers who prefer those of the older type. They are rather lower in cost, and the size of the picture that may be made with an enlarger of this kind is only limited by the dimensions of the dark-room and by the size of the bromide paper. There is also considerable facility for the control of the projected image, in the matter of masking or local shading during exposure. In addition, these enlargers have sufficient extension of bellows to allow of their being used for reduction. This latter is a valuable feature if lantern slides are being made from quarter-plate or larger negatives. In their best form these enlargers are also provided with a carrier that permits the negative to be displaced from the vertical position. This is useful for the correction of vertical lines on the negative which converge owing to the camera having been tilted when exposing. Lighting Systems. It is most important that the nega¬ tive should be evenly illuminated. As already stated, this is done by means of a condenser, the latter collecting the light rays from the illuminant and sending them forth so that the margins of the field are as evenly illuminated as the centre. In other cases this is done by means of a system of reflectors. IBoth of these systems have their claims for consideration. The condenser system offers the advantage of high speed, and reduces exposure. The diffuser is kinder to small blemishes on the negatives, as well as to hand-work or retouching, the latter being less in evidence. In one or two models the two systems are combined, with the result that the advantage of high speed remains, while the reproduction of small blemishes, hand-work, or grain in the negative, is avoided. The Lens. As with the camera, the optical quality of the lens is of the first im¬ portance. The finest definition in the negative can be lost by the use of an objective of indifferent quality. Many photographers are not aware of the importance of a good lens, as is evident b}?' the number of enlargements that exhibit poor definition. If the photographer is possessed of a good lens on his camera, it is generally possible to use the same instrument on the enlarger. Illuminants. In most cases an electric lamp of the pearl type is employed for en¬ larging, but where, as in country districts, electric current is not avail¬ able, the photographer has to consider other light sources. Incandescent gas is quite suitable for horizontal enlargers, but not all the vertical models are adapted for it. The same applies to spirit vapour and, acetylerie gas. Miniature Enlargers. The user of a miniature camera will find that by employing an enlarger bu ilt for the size of negative used work will be enormousl};' facilitated and the final prints will be better. It is true that an enlarger of quarter-plate size can, if necessary, be used for miniature negatives, but big enlargements will be difficult or even impossible to make. In a vertical enlarger the upright pillar will not be tall enough to give the high degree of magnifi¬ cation required, while the size of the dark-room may set a similar limit when using a horizontal enlarger. Further, there is some difficulty in seeing the image on the easel when the apparatus and the easel are sepa¬ rated by the great distance necessi¬ tated by the use of a large apparatus for small negatives. 449 ». 7