. Radiography, x-ray therapeutics and radium therapy . bject, reduced prints may be obtained bv theuse of a reducing lantern. By using an apparatus of tlds kdnd it is possibleto obtain in a small space prints of the largest plates. These may be mountedm series on a large mount, and despatched to the physician or surgeon incharge of the patient. These reduced positives are quite sharp, show allthe detail of the large prints, and may be included in the notes of a when dried should be carefully cleaned and particulars attached tothem. When examined and reported on, they should be file
. Radiography, x-ray therapeutics and radium therapy . bject, reduced prints may be obtained bv theuse of a reducing lantern. By using an apparatus of tlds kdnd it is possibleto obtain in a small space prints of the largest plates. These may be mountedm series on a large mount, and despatched to the physician or surgeon incharge of the patient. These reduced positives are quite sharp, show allthe detail of the large prints, and may be included in the notes of a when dried should be carefully cleaned and particulars attached tothem. When examined and reported on, they should be filed away andindexed. The card index system will be found most useful for this cards may be printed to suit individual requirements. 102 RADIOGRAPHY Further Points in Exposure and Development It is worthy of note that a practical knowledge of photography is veryhelpful to theradiographer, and in no part of his work more so than in thedevelopment of his plates. Fortunately for the majority of workers whose An exposure of 12 sees. 10 4 „. An exposure of 28 sees. 24 „ 20 „ 16 „ 1-2 ., 8 „ Fig. 87.—To illustrate the latitude of exposure. Eacli of tlie twelve exposures gives a goodnegative. These exposures were made with a moderately soft tube. knowledge of pliotography is slight, considerable latitude in the exposuretime exists. First Experiment.—In the course of a number of experiments performedfor the purpose of ascertaining this point, it was found that if a limb of eventhickness was radiographed, being divided into areas which allowed of twelveexposures of different dvuation, commencing with 2 seconds and ranging upto 20 to 30 seconds, useful negatives were obtained from each exposure. PRACTICAL POINTS IN EXPOSURE 103 The development was necessarily uniform, as all the exposures were on theone plate. Second Experiment.—On this occasion the same duration of exposurewas given to each part, and it was found that useful negatives were obtainedby varying
Size: 1324px × 1886px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookpublisherlondo, bookyear1915
