Amateur Photographer & Cinematographer (1933)

Ihf AMATEUR PHOTOGRAPHER €> G CINEMATOGRAPHER g the introduction of some shading, which requires no special knowledge of art. If he can improve the blackboard representation, scholars, juvenile and adult, will bless him. Dear old Dublin. We spent the last days of July in Dublin (writes a correspondent), a city that grows on you the longer you stay in it. At first sight it looked as if it wanted everywhere a fresh coat of paint, but presently we came to rejoice in those low tones, that subdued air, those gentle shadows. There is certainly in the Dublin streets opportunity for pic¬ tures at every turn, the buildings and greens of Trinity College in the very centre of the city are lovely, and so is the view at the end of some rather commonplace Dublin Street, beyond which lies a vista of ver¬ dant green and sloping hill. But best of all is it to stand on the O’Connell Bridge in the evening and watch the soft reflections of the setting sun in the waters of the Liffey. We saw no photographer ever at that spot, but there were lighting effects which were worth studying, while the miles of quays on either side are full of interest, and not infrequently of charm. Some may be doubtful of Dublin, and its reception, but we were among two thousand English and Scottish folk who descended on the city, and from none of them did we hear that they had noticed a gesture or an inflection that did not convey the innate courtesy and warm¬ hearted friendliness of the Irish folk. The Other Way Up. Are judges at exhibitions governed too much by symmetry in photo¬ graphs ? We have the testimony of one who acted as judge that his two colleagues outvoted him in giving the award to a picture of a boat lying becalmed on a Norfolk broad, with a beautiful reflection in the still water, and the thing which appealed to them was that it was so admirably done technically that it looked just as well the other way up ! August 9th, 1933 Infra-red in Medicine. The scenic effects to be obtained by means of infra-red photography have ceased to be a novelty for the newspapers, but infra-red is finding its application in practical ways increasingly. Recently we saw some slides from infra-red photographs designed to illustrate medical sub¬ jects. They showed in a startling manner changes in the skin indicative of disease, which the eyesight or the ordinary plate would fail to notice. Faced with the infra-red plate the dermatologist would be in no diffi¬ culty as to his diagnosis of the condition. Again, in the normal, the changed appearance of the human body under infra-red is instructive. For example, in the ordinary photograph the fine net¬ work of veins which converge on the female breast are not visible, but under infra-red they stand out as clearly as rivers on a map. Infra¬ red photographs are finding their way into our medical schools, where they will be invaluable for teaching purposes. /^acts and /formulae : NEW SERIES A selection of useful hints classified according to subject LIGHT FILTERS. II. The filters used in colour photography must be much more carefully selected and adjusted than those that serve for ordinary monochrome work with orthochromatic pr panchro¬ matic plates. For screen-plate colour photography the filters made for each of the processes available should be invariably used. Of equal importance is the balance of the three filters used in three-colour photography. * * * Filters suitable for landscape and portraiture can be pre¬ pared in a fairly simple manner, although cleanliness is very important. Take a thin, flawless lantern plate, fix it out, wash and dry. The dried plate is immersed for from two to three minutes in a suitable dye, rinsed in water, and put to dry in a dust-free place. * * * A good yellow dye for general use with orthochromatic plates is : Filter Yellow K .. .. .. .. .. 1 part. Distilled water . . . . . . . . . . 200 parts. For a clear bright screen giving very slight increase of exposure, Tartrazine may be substituted for the dye above. If Auraulia is used instead the filter has a tendency to orange. * * * When filters are made in this manner they should be bound up with a thin cover-glass as is done with lantern slides. It is still better to cement the two glasses together with Canada balsam thinned down to the consistency of glycerine. * * * Safelights for dark-room lamps are essentially filters which cut out from the light those rays to which the material (bromide paper, plates, etc.), is sensitive. The character of the light, as well as its strength, is a factor in arriving at a suitable screen to ensure safety. * * * Coloured papers, specially prepared for the purpose, can be bound up, passe-partout fashion, between two pieces of glass. Single sheets, two sheets of the same or different colours, and so on, are used, generally with a sheet of tissue paper added as a diffuser. * * * PlAin glasses may be coated with dyed gelatine. The gelatine should be soaked in the water, melted by placing the vessel in a water-bath, and the dye stirred in. The mixture is coated evenly over the glass. * * * For bromide paper two glasses should be coated with the following, and bound up face to face : Gelatine . . . . . . . . . . . . 4 oz. Water . . . . . . 5 J oz. Tartrazine . . . . . . . . . . . . 20 grs. * * * For rapid plates two glasses should be used with the follow¬ ing coating : Gelatine . . . . . . . . . . . . A oz. Water . . . . . . . . . . • • 5i oz. Tartrazine . . . . . . . . . . . . 16 grs. Rose Bengal . . . . . . . . • . S grs. If the plates are orthochromatic a third glass should be used with 7 grs. of Methyl Violet in the usual gelatine solution. * * * In all the above preparations the dyes are more easily and evenly incorporated with the gelatine if they are added from stock solutions of known percentage. 6 122