232 



PHOTOMICROGRAPHY 



Equally good results can be obtained without a con- 

 denser at all, by throwing light through the negative 

 from a reflector in the manner described in Chapter VII. 



Fig. 70 



SIMPLE ENLARGING APPARATUS 



Fig. 70 shows the apparatus arranged for enlarging. The 

 light from a reflector is not nearly so intense as that 

 obtained when a condenser is used, and the exposures 

 required are much longer. 



The bromide paper is pinned upon an easel, and it is 

 evident that no actinic light beyond that forming the 

 image must be allowed to reach it. If enlargement is 

 done in a dark room, a curtain or focussing-cloth can be 

 used to cut off extraneous light from the lamp ; a rod 

 on which a curtain can be carried is shown in Fig. 69. 

 A better plan is to make use of a bellows between con- 

 denser or reflector and lens, as in Fig. 70. The radiant 

 in any case is enclosed. In order to carry out enlargement 

 in a lighted room a bellows must be used to protect the 

 bromide paper. In Zeiss' large camera there is a central 

 panel to carry the lens, the bellows on one side of it 

 carries a suitable holder for the negative, while the bro- 

 mide paper is placed in a dark slide fitting the other 



