ORTUOCHROMAT1C PLATES IN PORTRAITURE.
The use of orthochromatic plates for portraiture is by no means general, nor are they necessary for the usual run of work. Their employment in certain cases, however, is to be recommended, as, for example, in photographing fancy costumes containing combinations of colour whose proportionate contrast might otherwise be altered. Where also the costume consists entirely of red, a plate prepared with cyanine will prove an ad vantage in rendering more shadow detail.
It is seldom, however, that the use of a screen is necessary, as few of the ultra violet rays are present in the studio, being generally abstracted from the light before it reaches the lens. The use of yellow blinds is invariably sufficient for the pur pose of reducing the blue rays. The use of such blinds is also effective in render ing freckles less apparent, even when using ordinary plates, but the consider able increase in exposure tends to coun teract any real benefits that might arise. When, therefore, this end is in view the orthochromatic plate by its superior sen sitiveness will be of great service. The
freckles will be much less apparent on an orthoehromatic plate even when no yellow blinds arc When a studio is fitted with ordinary blinds the effect may be easily arranged for by throwing a length of yellow muslin over the _head screen, and in this way the screening effect may be localised or confined to the face. Again, when photographing sitters with golden or auburn hair, orthochro matic plates will give a far more correct rendering. It will be seen, therefore, that, although these plates are not recom mended for general use, yet a knowledge of their manipulation is at times essential. The fact that so many photographers still indulge in rule of thumb development, judging the density by continual viewing against the light, has no doubt much to do with the unpopularity of such plates ; since, worked in this way, they are • sure to produce more fog than is even allow able in portraiture. Developed, however, with a light which passes a minimum of actinic rays, and by the time system, there should be no trouble.