PHOTOGRAPHY.

Auckland Star, Volume XLII, Issue 137, 10 June 1911, Page 16

PHOTOGRAPHY.

FILM VERSUS TLATE. The battle between the glass plate and the film is perennial. It may be well to remind those who are wavering between the two as to the determining factors. The film has the advantage of lightness, small liability to fracture, and less room occupied, while the.glass plate is cheaper, easier to handle, and gives no trouble in the matter of keeping fiat. Thus the film is for the traveller, while the glass plate is for the homeworker. As to after-treatment—e.g.. intensification, re-touching, etc.—the plate has the balance of advantages. Now and again it is found that a film apparently refuses 'to bleach, etc.. for no apparent reason, and is cast aside as hopeless; but the chances are that it is only a time difference, and that if the film be given plenty of time it will behave just like an ordinary plate. Therefore, do not east aside a film until it has been well soaked in plain water and allowed extra time in the other baths— not excepting the final washing. LONG OK SHORT FOCUS LENSES. The question is often asked as to what is the best focal length of lens to use for any certain size of plate; and also whether the long-focus lens is really necessary. Now. perhaps, the one fault to be found with the present-day form of .camera,, and more, pspedialjy ,tho folding pocket type, is that in many cases they are fitted with lenses of too short a focal length. The best lenses for various plates are, for quarter-plate a lens of not less than 5i in., focal length, for 5 by 4 plate one of Ojin., and for half-plate,"one of Sin. These lenses are suitable for what may be termed general snapshot work, but for anything of a special nature, that is where we have in our picture some particular object which is to form the centre of interest in the photograph, and for portraiture and architectural work (where space permits) the long focus lens is a necessity. The chief reason for this is that a more correct rendering of the perspective and proportions of the subject is obtained. In the case of a portrait taken with a short focus lens the parts nearest the camera, probably the hands and feet, will show in the photograph much larger in proportion to the head and body than they really are, whereas if the same subject were taken with a lens of double tbe focal length the rendering of proportion would be correct. Again in architecture, if n building be taken with a short focus lens then the doors and windows nearest the camera are rendered too large in proportion to the part of tbe building farthest away, which is dwarfed in size, nnd the perspective of the picture is incorrect. Where sufficient camera extension is available the use of a lens is advisable giving three different foci, that is. an unsymmetrical doublet such as the Zeiss Double Protar. the Ballmeyer Stigmatic. or the Watson Iloiostigmat lenses. Although these lenses are somewhat expensive, they are good investments; but there are many other makes on the market nt much lower prices if the cost of those mentioned is too high. For cameras of short extension only, the use of the Bis-Tclar lens or the ballmeyer Adon in conjunction with the normal lens ia recommended.