Saturday, May 17, 2008

EX CATHEDRA: Continuation

Dark-Room Lighting.

           We recently were in the dark-room of a photographic friend whose amateur experience in electric wiring and battery making had been apphed in the provision of what he regarded as luxuries in the way of illumination. We are not so sure but that for a commercial dark-room, there were little more than the necessities for minimizing waste of labour. We should explain that our friend's dark-room, which was of ample size, and had the customary developing bench in one corner, had cupboards the contents of which were clearly seen by means of a little yellow electric bulb worked from a battery and connected to the latter so that the opening of the door completed the electric circuit whilst its closing the light off again. In many commercial dark-rooms where from lack of space elsewhere things are kept which are not needed in development operations a device of this kind would often save the time of a second assistant who might be wanting them whilst the dark-room was in use. Naturally enough our friend's room was fitted with two types of lamp, one with the safe-light nearly vertical the examination of negatives, and another of the horizontal pattern for use in the development of prints. Another fixture, and one which we have regularly used our self, is a ceiling light consisting of a fairly large lamp I a foot or so from the ceiling with its safe-light uppermost. The illumination, after its reflection from the ceiling provides a weak, but safe, and very comfortable light throughout the room.


           The passé-partout method of framing may very reasonably be thought to be one which will retain its popularity - certainly among amateur photographers and, no doubt, among the customers of professionals, to whom, however, it has not been offered as freely as its artistic possibilities warrant. It is sometimes astonishing to us to notice the ugly designs of frames which are shown in the show windows of photographers whose taste, judging from their own work in portraiture, might be thought to be a good deal better. The passe-partout with its ready adaptability to the key and colour of the print is particularly fitted for the display of window specimens, and, a* we have said, might well be offered to the customers of a studio more than it has been. Perhaps the manufacturers may do something towards further popularizing this form of framing; the altogether charming metal edging which for some year or two now has been on the market is one way of overcoming an objection to the passe-partout, viz., the impermanence of its paper binding. Messrs. Butcher have done something in the same direction by providing the slender frames, which are practically more or less solid surrounds for passe-partouts. More might certainly be done in this way by providing in one form or another a frame for the passe-partout which need only be of the lightest construction, any hanging tabs or rings ere attached to the back of the passe-partout itself, and the accessory frame thus relieved of any weight.

Fastest Fixing.

           Among other suggestions which we recently made to a correspondent who sent up a batch of stained paper natives was that of using a bath of the maximum fixing speed. Where, as in the case of such negatives, the process of fixing cannot be seen by the eye it is more than ordinarily necessary to arrange matters so as to secure complete fixation. As was ascertained some years ago by Mr. Welborne Piper in the course of a lengthy series of experiments, a fixing bath of 40 per cent, strength, that is to say, 8 ozs. dissolved, water to make 20 ozs. of solution, fixes more rapidly than any which is weaker or stronger. Although these experiments were made with a particular emulsion, our own experience with plates of many different makes has shown us that for practical purposes the strength of bath abovementioned may be taken as that which fixes in the shortest time. Obviously more hypo is required to make up a. bath of this strength, but, setting aside loss from sheer carelessness, such as splashing the solution about, there is no reason to believe that a bath of this strength is any less economical in use than one containing, say, only 4 to 6 ozs. in a pint of water. We have yet to find a plate with which a bath of this maximum strength cannot be used. In the case of papers it may easily happen that frilling or blisters may arise from the use of a fixing bath of this strength, although in our experience such effects have been very rare.

An Enlargement Attachment.

           By those photographers who require to make an enlargement only on comparatively rare occasions the studio camera may be very suitably employed. The addition of a small attachment serves to convert it into an enlarger capable of making a print of the size of the largest plate which the camera will take. The attachment consists simply of a box mounted to slide, by means of a panel, in the grooves which carry the camera lens. The box is provided at one end for the reception of the negative to be enlarged and at the other with an R.R. lens of focus suitable for the purpose. The distance between the diaphragm of the lens and the negative will naturally be adjusted in correspondence with the degree of enlargement required. For this there is the very simple rule that the distance will be one focal length plus one-half one-third, one-fourth, according as the enlargement is to I three or four times. Where the studio does not provide a ready outlook to a clear sky for the illumination of the negatives, the necessity of tilting the camera may be avoided by using a reflector in the shape of a mirror or even a white card placed at an angle of 45 to the plane of the negative. An alternative where electric light it used in the studio may consist simply in placing this reflector, or rather the white card, a few inches below an, arc lamp or a half-watt bulb.

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