|
Main
- books.jibble.org
My Books
- IRC Hacks
Misc. Articles
- Meaning of Jibble
- M4 Su Doku
- Computer Scrapbooking
- Setting up Java
- Bootable Java
- Cookies in Java
- Dynamic Graphs
- Social Shakespeare
External Links
- Paul Mutton
- Jibble Photo Gallery
- Jibble Forums
- Google Landmarks
- Jibble Shop
- Free Books
- Intershot Ltd
|
books.jibble.org
Previous Page
| Next Page
Page 21
D.
Bromide of potassium. 1 ounce.
Water to make up to 10 ounces.
I have here two half-plate films exposed at 8:30 A.M. to-day, one with
five and one with six seconds' exposure, subject chiefly middle
distance. I take 90 minims A, 10 minims D, and 90 minims B, and make
up to 2 ounces water. I do not soak the films in water. There is no
need for it. In fact, it is prejudicial to do so. I place the films
face uppermost in the dish, and pour on the developer on the center of
the films. You will observe they lie perfectly flat, and are free from
air bubbles. Rock the dish continually during development, and when
the high lights are out add from 10 to 90 minims C, and finish
development and fix. The negatives being complete, I ask you to
observe that both are of equal quality, proving the latitude of
exposure permissible.
I now coat a piece of glass half an inch larger all round than the
negative with India rubber solution (see Eastman formula), and
squeegee the negative face downward upon the rubber, interposing a
sheet of blotting paper and oilskin between the negative and squeegee
to prevent injury to the exposed rubber surface, and then place the
negative under pressure with blotting paper interposed until
moderately dry only.
I then pour hot water upon it, and, gently rocking the dish, you see
the paper floats from the film without the necessity for pulling it
with a pin, leaving the film negative on the glass. Now, the
instructions say remove the remaining soluble gelatine with camel's
hair brush, but, unless it requires intensifying, which no properly
developed negative should require, you need not do so, but simply pour
on the gelatine solution (see Eastman formula), well covering the
edges of the film, and put on a level shelf to dry.
I will now take up a negative in this state on the glass, but dry, and
carefully cut round the edges of the film, and you see I can readily
pull off the film with its gelatine support. Having now passed through
the whole of the process, it behooves us to consider for a few minutes
the causes of failure in the hands of beginners and their remedies: 1.
The rubber will not flow over glass? Solution too thick, glass greasy.
2. Rubber peels off on drying? Dirty glass. 3. Negative not dense
enough? Use more bromide and longer development. 4. Gelatine cracks on
being pulled off? Add more glycerine. 5. Gelatine not thick enough?
Gelatine varnish too thin, not strong enough. 6. Does not dry
sufficiently hard? Too much glycerine.--_E.H. Jaques, Reported in Br.
Jour. of Photography._
* * * * *
HOW DIFFERENT TONES IN GELATINO-CHLORIDE PRINTS MAY BE VARIED BY
DEVELOPERS.
The following formul� are for use with gelatino-chloride paper or
plates. The quantities are in each case calculated for one ounce,
three parts of each of the following solutions being employed and
added to one part of solution of protosulphate of iron. Strength, 140
grains to the ounce.
_Slaty Blue._
1.--One part of the above solution
to three parts of a solution of citrate of ammonia.
_Greenish Brown._
2.--Citric acid. 180 grains
Carbonate of ammonia. 50 "
3.--Citrate of ammonia. 250 grains.
Chloride of sodium. 2 "
4.--Citrate of ammonia. 250 grains.
Chloride of sodium. 4 "
_Sepia Brown._
5.--Citrate of ammonia. 250 grains.
Chloride of sodium. 8 "
Previous Page
| Next Page
|
|