The Dictionary Of Photography

A True Historic Record Of The Art & Practice Of Photography 100 Years Ago.

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Diffraction or Inflection                                Diffused Light
For Purple Tones.
a-Napthylamine .........
Oxalic acid......         .....
Distilled water         ..........
12
parts.
1*2
M
1,000
M
12
parts.
1,000
>ยป
For Blue Tones.
Eikonogen Distilled water
For Brown Tones.
Pyrogallol ... .. ......... 12 parts.
Distilled water         ............1,000 ,,
As soon as the colour is sufficiently developed, the material should be well washed in water, and dried. Napthylamine has an intense and characteristic smell which may be removed from hands and dishes by using the nitrite sensitising solution. For purple pictures the material should be rinsed in dilute solution of tartaric acid and dried without further washing. For obtaining prints on paper it is advisable to size the paper well first with a 2 per cent, solution of gelatine with a little chrome alum, and allow this to thoroughly dry, and then sensitise by floating on the hot nitrite solution, care being taken that none gets on the back. The after-treatment is the same as for materials. Transparencies and opals can be made by coating glass with
Primuline ...        ...        ... ...        ... 80 parts.
Gelatine ...        ...        ... ...        ... 480 ..
Chrome alum           ...        ... ...        ... 2 ;,
Distilled water         ...        ......        ...9,600 ,,
allowing to set and dry, and then sensitising by immersion in the nitrite solution. Prints produced by this process are permanent, unless exposed to brilliant sunshine. Designs in different colours can be made by thickening the developers with boiled starch and applying with a brush. Wool and silk require longer exposures than cotton or linen. (See Feertype.)
Diffraction or Inflection. An optical term used to denote the bending of the rays of light when such rays pass by the edges of an opaque body.
Diffused Light. Generally, in opposition to direct light. It is the only light which should be used for Portraiture (q.v.).
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