PHOTOGRAPHY.

Auckland Star, Volume XLII, Issue 209, 2 September 1911, Page 15

PHOTOGRAPHY.

BRILLIANT PLATINUM PRINTS. It may not be generally known, says "Photography and Focus," that a trace of potassium bichromate added to tSifc potassium oxalate solution in which platinum prints arc developed will giv» much brighter prints than are to be obtained without it. Ammonium bichromate is better than the potassium salt, and a single drop of a 10 per cent, solution of ammonium bichromate to every two ounces of the platinum developer will be found quite sufficient. If too much is added, the prints will be harsh and wanting in gradation. Nothing is gained by such an addition when the negative is » good one and suitabk for the process; but when it is too thin to print well in platinum in the ordinary way, the addition of the merest trace yf the bichromate makes a great difference. After development the prints are placed in the usual acid baths and washed. CHANGING PLATES ON TOUR In some up-to-date hotels a dark room is usually provided for the use of its patrons, but photographers in out-of-the-way places experience considerable difficulty in adapting themselves to the conditions prevailing in less ambitious quarters. No trouble, however, should be experienced in changing plates at nigki time in an ordinary room, provided no, direct light is allowed to reach the plate. 1 have changed hundreds of plates under similar conditions, and the only precau-l tions taken kere to draw the blind and do the changing in the darkest corner of the room. In some instances sufficient diffused light from the moon has penetrated: the room to enable me to dispense with a red lamp without, in any way, affecting the plate. It is, however, advisable to take every precaution to guard against fog, and the plates should be changed as expeditiously as possible. If the dish is covered immediately after flowing the developer over the plate, development may be conducted under these conditions with a greater degree of certainty than prevails in many so-called dark-rooms. NEED OF SKY IN LANDSCAPE. With not a few photographers it is quite a long time before they realise the fact that a blank white paper sky part of a landscape print is not only impossible as a presentation of sky or cloud, but also in 99 per cent, of such prints a blank paper space fatally upsets the tone values of the other parts of his print. There are two ways out of this trouble. First we may—and most advisedly should —use a colour sensitive plate and colour screen when taking the negative. Of course, it does not always happen that if we do secure the sky part of the scene on the same plate as the land part we have got the best sky for the picture, but at any rate the sky and clouds present at the moment are certain to be vastly better than blank white paper; in any case we can always stop out the sky part when so desiring. Secondly, it is too frequently assumed that cloud forms must always be introduced where sky printing is resorted to. But this la a great mistake, for in many —perhaps the majority of —out-door subjects dealt with by photographers a delicately-graduated plain, i.e.. cloudless, sky is preferable. Without the use of diagrams and more space than can be here aftwded it would not be possible to gire practical instruction in cloud and sky printing. Just one word of warning is needed. The beginner is usually agreeably surprised to find out how easy the whole business is, and thus is tempted to go at it somewhat carelessly with the result that from a blank white sky he swings the pendulum to the opposite extreme, making his sky and elands very mueh too dark and forceful