Amateur Photographer & Cinematographer (1936)

H AMATEUR PHOTOGRAPHER fa 6 CIHEMATOGRAPHER a Ensuring Film-Wind in a Leica There are a few simple precautions that will avoid any possibility of accidental double exposure with a Leica, due to the him not advancing between exposures. Jf this happens it will mean thirtv-si.x exposures one on top of another, with over five feet of clear film as a memento .of the incident. — I know, because it was one of the first spectacular feats that 1 achiev¬ ed with my camera. The film in a Leica camera is advanced by sprockets rotated by means of the winding knob, and there is also a fric¬ tional take-up on the winding spool. If the perforations are broken on the film the sprockets can rotate without moving the film on, or if the film has become jammed, then once the sprockets are free, there is nothing to prevent the winding knob being turned while the film remains stationary. This is detected by the failure of the back-winding knob to turn in an anti¬ clockwise direction, but if short ends are being employed in a metal filmchamber the roll of film may have become loosened in the chamber, so that several exposures are made before the slack film has been drawn off and the centre spool begins to rotate. To ensure against any such trouble, all film ends should be examined against broken perforations, and if the film has been cut from a length, it is essential to There is no doubt that the vogue of carrying the miniature camera in an ever-ready case suspended by a short strap round the neck is very popular, as it is both practical and comfortable. The same idea can be adopted for other cameras, using zip purses, but they must pos¬ sess some means of securing the neckstrap, either by the carrying handles or with special loops of leather or metal fixed for the pur¬ pose. Before clipping the strap on to the camera, slip on a stout rubber band about I in. wide and 3 in. long so that it is always on the strap. This secures the zip purse which is slipped upwards over the camera and the rubber band is pulled over both camera and case. This, of trim it without cutting through a per¬ foration. This is done automatically if the correct film-trimming template is Used for the purpose. When loading, the back should Le locked in position before any attempt is made to turn the winding knob. An or'er-nervous photographer is tempted to wind on a little film to see if it is going to engage before re¬ placing the lid of the camera, but in the case of the metal spool-cham¬ ber, locking the lid opens the light trap of the chamber at the same time, and therefore decreases the pull on the film itself. Another possible cause of non¬ advance of film is that the trimmed end may not have been properly pushed under the clip of the winding spool, so that the perforations are not in line with the sprockets. These difficulties should not arise if due care is taken when loading, and once the film has been loaded, the back-winding knob should be gently turned in a clockwise direction to take up any slack in the film roll, after which it can be readily seen if this revolves when winding off the fogged film. Any failure on the part of the film to advance usually takes place at the commencement of a new film. Once it has started, no further difficulty need be expected. Bernard Alfieri, Jun. course, means that the case is removed entirely while the exposures are being made, but if it is desired to keep the case always connected, then it is sug¬ gested that a small leather strap be sewn on the lower edge of the case with the rubber band in position. This will prevent the possibility of mislaying the case, it will be seen that the zip fas¬ tener cannot be drawn together as the two strap ends prev'ent this, so that any similar type of purse with or without fast¬ eners will serve equally well. A word of warning when using cam¬ eras suspended by the metal carryinghandle links. If the camera is on the heavy side and the links are thin, there is a danger of them bending outwards. December 23rd, 1936 Pan or Ortho ? The full sensitivity to colour of the panchromatic film results in ob¬ taining better correction with a filter of given depth than an orthochromatic film can offer, while at the same time requiring less increase of e.xposure. Where the pan. film may give all the correction required with a pale filter requiring about times increase in exposure, an ortho, film may need a deeper filter requiring the exposure to be multiplied by three or four. In these circumstances a pan. film of speed 500 H. & D. may actually allow of shorter exposures than an ortho, film of 1,000 H. A D., and still give equally good colour rendering. Confirmed users of filters will do well, therefore, to consider the pros and cons of changing to a panchromatic film for habitual use. For Sharpest Pictures. To set against this there is the not uncommon experience that an ortho, film will often yield pictures just a shade sharper in definition than those which a pan. film will give. This is partly due to the fact that red light, to which only the pan. film responds, is scattered more than light of other colours, and so tends to superimpose a microscopic blur upon the image. Sometimes it is due to slight lack of correction in the lens ; it is customary to design a lens so that it brings blue and yellow-green rays to a focus at exactly the same point, these being the two colours to which ortho, film is, or has been in the past, most sensitive. In some lenses this correction has not been so completely made for red rays, with the result that when by using pan. film we allow the red rays to enter into the image formation, their contribution is to a minute extent out of focus, so reducing the sharpness of the negative as a whole. A. L. M. S. Filing 35 -mm. Negatives. ESSRS. E. LEITZ, ltd., of 20, Alortimer Street, W.i, have re¬ cently introduced two inexpen¬ sive containers for filing and indexing negatives on 35-mm. cine film. The " Leica Wallet Container ” ac¬ commodates one 36-exposure length in nine sections of four negatives each. The strips slide into a series of pockets of transparent paper which fold up, concertina fashion, into an outer enve¬ lope of stout paper. All negatives can be viewed simultaneously without re¬ moval from the container, which is sold at the very modest price of sixpence. The " Leica Negative Album ” takes twelve complete films of 36 exposures each, again in four-exposure lengths. The album, which measures 7^x6 in., contains three sections, each of which contains thirty-six transparent envelopes. There is also a set of index-sheets for identifying and describing every negative. It is covered in linen card in such a way that negatives cannot work out from the pockets, and closes with a snap fastener. It is priced at 4.S. 6d. Carrying the Miniature Camera A. J. MILNE. 645 16