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The Barnet Book of Photography A Collection of Practical Articles

Platinotypes may be toned to a red brown by uranium nitrate


Castille soap 40 grains Bicarbonate of soda 80 grains Water, hot (180 deg. F.) 1 pint

This will clear the whites and intensify the colour generally.

Platinotypes may be toned to a red-brown by uranium nitrate, or to a bluer colour with chloride of gold. They may also be intensified by pyrogallic acid or hydroquinone, but as the purpose of this article was merely to give simple working instructions for platinotype printing for the beginner, he may defer the consideration of such side issues until he has become _au fait_ in the production of a good platinotype print.

_A. Horsley Hinton._

_Contact Printing on Bromide Paper._

[Illustration]

It is well to bear in mind at the outset that bromide paper is extremely sensitive to light, almost as much so as is a rapid dry plate. For this reason, it is obvious that it must not be carelessly exposed to actinic light. All manipulations except the actual printing must be conducted by red or yellow light, such as is allowed to pass through glass of these colours.

For evenness of result, it is better to use a lantern than daylight, because the fluctuation in intensity of the latter is very misleading

and liable to lead to failures through over or under development.

The actual colour of the light, also, is of far more importance than one would suppose: ruby light tends to give one the impression that development is complete long before that is the actual case; it is also somewhat more difficult to handle the paper satisfactorily by this light than by a good yellow.

For these and other reasons I strongly recommend the use of yellow light, a thoroughly safe one being given by gas or lamplight passing through one sheet of yellow glass and one thickness of "canary medium."

This light, while being absolutely safe, gives such perfect illumination that it is as easy to control and estimate results as it would be by ordinary unfiltered gaslight.

If a ruby glazed lantern is already in use for negative work, it can readily be prepared for bromide printing by merely removing the ruby glass and substituting the yellow and canary medium. With these brief hints as to illumination, let us consider the entire process in its various stages.

_Unpacking the Paper._--The sensitive paper is generally packed in envelopes sufficiently opaque to protect it from the admission of light. The packet must be opened in the dark-room from which _all_ light (even stray streaks beneath the door) is excluded, excepting only that given by the yellow glazed lantern. The outer envelope being carefully undone, an inner cover will be found and these wrappers should be placed on a dry table while a sheet of the paper is removed.

It is a good plan to have a "light-tight" box (obtainable from any dealer) in which to put the paper after unpacking it; this prevents loss of time and awkwardness of handling in having to replace the paper in its wrappers each time a piece is withdrawn for use.

When several prints from one or more negatives are required, it is an excellent thing to have two of these boxes, one for the unexposed paper and one in which to put the prints as made until all are ready for development.


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