The Wichita daily eagle. [volume] (Wichita, Kan.) 1890-1906, 1898-01-11

given on account of the mass of snow.
Experience tends TO prove that the light
given off by the snowy surface is abuot
half that falling upon it. 1t is common
ly stated that the exposure for mega
tive Of a snow scene should be about
equal to that given on the same scene in
summer, and this appears approximately
correct. Now, seeing that the light at
widday in winter has only one-third to
one-fourth the Photographic power of that
at the same time in summer, ii is evident
that the snow must reflect an enormous
amount of light as compared with objects
generally.
WHEN OvER-EXPOSED.
Negatives that are too thin to yield
good prints can always be easily intensi-
fed, says Wilson's Magazine, providing
one precaution be observed, viz: that they
are perfectly fixed as it is the invisible
silver salts left in the film that cause
stains, and not on account of any slight
trace of hypo that may be lift in. Thin
negatives are of two sorts-those which
have been properly exposed but not de-
veloped far enough to allow of a proper
density being obtained. and those which
are over-exposed and which, being devel-
oped with a normal developer, cannot be
got sufficiently Opaque. When it is seen
that a negative is fiat and thin upon TAX
ing from the fixing bath ii should be wash
ed for few minutes and then placed in
clean solution of hypo and left there for
at least 10 minutes, then washed for the
usual time and dried. Negatives that are
to be intensified can be done whilee wet,
but it will be found that the best results
are to be obtained if the negative be al
lowed to dry first. For intensifying gela-
tine negatives there is nothing better than
the mercury method, using a solution of
either sulphite of soda or carbonate of
soda with which to blacken the bleached
film, except in cases where an extra thin
negative is dealt with, in which case a
solution of iodide of potassium should be
used, which acts very energetically and
gives a much stronger negative. When a
negative has been stained in intensifying
it is usual to say that it has not been pro-
perly washed; this is not so in the great
majority of cases. The fact is that it has
not been properly fixed. If a negative,
fixed as recommended above. be rinsed
back and front under the tap for five min
utes it can be intensified with steam as
even should there be little hypo left in
the film and cause scum, that scum can
be removed with a pad of cotton wool, but
the negative on blackening will he Iree
from stain. On the other hand remove the
negative from the fixing bath directly it
is cleared, give it an extra washing and
use hypo eliminator, but when it is in
tensified it will be stained. Therefore, it
is imperative to see that negatives inten-
ded for intensification are properly fixed.
that being more important than extra
washing.
SLOW DEVELOPMENT ADVOCATED.
DR.. A. Meydenbauer advocates slow de-
velopment in a very diluted developer and
gives two formulate, one for instantaneous
exposures and the other for time exposu-
res with slow working lens. For short ex-
posures in strong light he uses the fol-
lowing formula:
100 parts sulphite of soda Q-10).
100 parts carbonate of potash do.
5000 parts water.
IL parts of dry hypo.
For long exposures with slow instru-
ments he prefers the following proper
tons:
100 parts sulphits of soda Q-10).
100 parts carbonate of potash 90.
1000 parts of water.
parts of pyro dry.
This developer is so weak that II might
be called dirty water. 1t will keep sew
eral days, and can be strengthened by adj
ding a small quantity of pyro. The mega
tives are very harmonious, and the colors
are rendered better than when strong So
lutions are used.
MEASURING REFLECTOR LIGHT.
The following table shows the amount
of light reflected from the various sub
stances as compared with that which
falls upon their surfaces, and has been
compiled by DR.. Sumpner:
White blotting paper. g per cent
White cartridge paPer..-..-..-. 50 per cent
White tracing paper----.-...... p per cent.
Ordinary foolscap,.-....----... 40 per cent
paper...--...... 80 to, 20 per cent.
Yellow wall paper.........---. 40 per cent
Blue paper.......-.....----..-.- . per cent
Dark brown paper.-.-.---..-- l3 per cent
Dark chocolate paper.......... per cent
Planed deal, clean.-. 40 10 % per cent
Planed deal, dirty....-.-.-.-. % per cent.
Yellow painted wall. dirty. % per cent
DARK ROOM HELP.
In photographing small natural objects.
such as fossils. dried plants and grasses,
etc, good results can be secured by az
r@---- 10 = -ah