PHOTOGRAPHY 



PHOTOGRAPHY 



otherwise wmil 

 Intense as if 1 1 

 a suitable ra} 1 I 



This ray-hltci i , „l 11 i II 1 1 , i i i 



cent solution of j. t issniiu bichiumjtt oi i putc ul 

 plane optical glass covered with a suitably stained col 

 lodion film sealed with an,)ther optical gl vss and pro 

 vided with a convenient mounting for slii>ping on the 

 lens. With this ra\ -filter and the isochroraatic plate be 

 fore alluded to, the yellow is slightly over-valued, but 

 the blue is given its proper relation. The beauty of 

 outdoor photographs is vastly increased by the use of 

 the plate and ray-filter mentioned, because a proper 

 color value is given to the sl<y, and the cloud forms are 

 preserved in all their attractiveness. If the subject be 



of light that p«ss 



1768. AdiustaDle , 



estand, horizontal position, 



1769. Adjustable camera stand, vertical positi 



a ii,-iivily !,>a,li-il i>eaeii tree, for instance, the accentua- 

 tion of the yellow, brought aliout by the use of the ray- 

 fllter, will give a needed slight exaggeration of color 

 value to the fruit, which, under treatment by an ordinary 

 plate, will be almost indistinguishable from the mass of 

 foliage. With the ray -filter the exposure required is 

 practically trebled. In this Cyclopedia, advantage has 

 been talten of isochroraatic plates in photographing 

 some of the subjects. The carnations, Plate IV, Vol.1, 

 show a variety of sha,ies properly rendered by the 

 means indicati-.l. Tlie di.hlia. Plate IX, shows the 

 rendering of ,lark r,-,l shii,iis in connection with green 

 foliage by tlic is...'hn.iii:,ti,- plate. The persimmim 

 platu (XXVIII) ill this v,iliiiiie also shows orange, yel- 

 low and red fruits as prop,-rIy rendered under this 

 isochroraatic handling, and the oranges (Plate XXIII), 

 including fruits frora the light lemon-yellow Pomelo to 

 the deep orange-red Tangierine, prove also the useful- 

 ness of the plate suggested. 



A difficulty known in photographic practice as hala- 

 tion raust also be counteracted if the fine detail of sub- 

 jects involving rauch light is to lie preserved. Plate 

 XXIX shows a milkweed pnd. fir-t a= photographed with 

 a plain isochroraatic plat.' nnl ~. .■,,., .1 as photographed 

 with the same plate, tr,-iihr I -,, ;,, i,, .liniiiiate halation. 

 (The two lower figures on tli< -,ii,p phiti' sliow the value 



Any dark substance which can be brought into absolute 

 optical contact witli tin- iM.si,ii(,i- smta,-,- c.f the glass 

 plate will answer, Imi ili. iii.,-t . ili.i. nt lia,-king is 

 provided by an a!,-<'lii'li'- ^mInih.m <,t -":\\'. to which lias 

 been added a mixtiir,- c.f . r\ i h. ..-in an. I am in, two re,i 

 aniline pigments having liiL'h . . i ' ! - | - . . Tljis 

 coating is easily applied, an : i ■i-.. 

 development; and the writ, t n i' , , i Multi- 

 cultural Photography uses i>,. in : i - n... k.d 



Kv.n Willi till- aid of the isochioniatic plate ai„l the 

 ra\ fill. I- III. |.li..t.igraphy of shades of red is difficult. 



sary to give a very much pri.l..iiL'.'.l .xpi.^nr.- t.. ..l.|,i'ts 

 containing red, and then to i.-iiau. ih. ..\ . i . > ]...-ure 



upon development by means ..t a -mi:.!!. ni|..iiin.i,-,l 



developing solution. Details i. ^nir.linL' 11. i- ai.- .ml of 

 place here, but may be obtained from the works cited at 

 the end of this sketch. 



Lantern-slides.— A few words may be added concern- 

 ing the production of lantern-slides, now of the greatest 

 importance in illustrative work. A lantprn-slide is a 

 positive on glass, and theri.f..r. i- i.ia.l.' ft-.. in a nega- 

 tive. It is made preferably .i. a -|... ml plate, much 

 slower than the regular phot.i_'ia|.lii.> .Ir;. |.laU-, because 



