Amateur Photographer & Cinematographer (1933)

[HE amateur photographer t, 6 CINEMATOGRAPHER a October 4th, 1933 mateur NEWS, NOTES AND MATTERS OF IN¬ TEREST FOR ALL CINEMATOGRAPHERS USING AMATEUR CINfi APPARATUS. Cinematography Reversal or Negative-Positive ? By S. E. L. MOIR. Many amateurs nowadays favour one particular process to the entire exclusion of the other. As the following article suggests, the neglected1 process is occasionally more suitable for the task in hand ; hence an excess of enthusiasm for any one kind of stock is a thing to be avoided. WHEN only one variety of film was available — and that merely orthochromatic — a question often asked was “ Should I make use of reversal or negative¬ positiveprocessing ? ” In many cases, the reply was influenced by the amount of success achieved with any particular make of film with which the worker may have had experience ; which was unfortunate, because there were both good and bad makes of the original orthochromatic film. Thus, if the worker had used only one manu¬ facturer’s negative-positive material — which he found dead slow, practically non-ortho., and extremely spotty, he would probably decide in favour of a reversal stock which he happened to know was good. On the other hand, had he used only one similarly bad make of reversal stock, he would most likely incline towards any nega¬ tive-positive system which was well spoken of by his amateur colleagues. Of course, the position was altered when certain “ reversal ” firms came out with the first panchromatic emul¬ sion. Would-be " pan ” users had no alternative but to employ reversal stock. But now we have panchro¬ matic film available in both processes the question once more is heard, “ Negative-positive or reversal ? ” by the reversal system, which was free from these annoying defects. If negative-positive practice lost some of its adherents in those early days, so did its then imperfect rival. Reversal stock gave little cause for complaint on the grounds of speed, colour interpretation or “ snowstorm ” spottiness, but it suffered more from granularity ; and, in addition, some of the manufacturers were at first unable to make compensating allow¬ ances for inaccurate exposures. The negative-positive people were always able to apply a fair measure of cor¬ rection for these — thanks to their experience with professional films, nor were their products quite so sus¬ ceptible to graininess. Nowadays, reversal film has been freed from both these disadvantages. Costly and highly-efficient machines automatically apply correction to both under and over-exposed shots, and they apply it to a degree which is almost impossible of attainment on the hand-controlled negative-positive printer. Similarly, much experiment has evolved “ anti-grain ” processing treatments and fine-grain emulsions. Little Comparison. At first sight, then, it may appear that there is some comparison between the quality of results achieved by the two processes ; but, actually, there is very little. In both cases, emulsions and finishing technique have been Absence of Defects. In order to arrive at a satisfactory solution of the problem, it is necessary to consider both processes in the light of common defects and the extent to which they are absent in the finished material. For instance, we have already touched upon slowness (which mani¬ fests itself in the form of an imperfect image), non-orthochromatic quality and spottiness. Fortunately/ these sel¬ dom give rise to trouble nowadays, but they formerly affected the nega¬ tive-positive process to such an extent that many workers were won over While action subjects similar to the above are still available the amateur cini worker should take advantage of every opportunity of trying new view-points . 22 321