Photomicrography 



51 



Summary 



1. Slide exposed paper face up into developer in tray (Fig. 59). Rock 

 continuously for 1 to 3 min. 



2. Remove to acid stop bath for 30 sec. 



3. Fix for 20 min in acid fixer (Fig. 60), rocking the tray at intervals. 

 Do not allow prints to remain overlapped. Use large dish and few prints. 



4. Wash 1 hr in print washer. 



5. Roll wet print onto polished surface, cover with canvas, and leave 

 to dry. 



PHOTOMICROGRAPHIC CAMERAS 



So far the discussion has concerned only the way in which photographic 

 images are recorded. It is now necessary to turn to the apparatus with 

 which these images are produced for record. 



The first step is of course to set up a microscope to operate with the 

 maximum possible efficiency. This has been fully described in Chapter 2 

 and no one should attempt to produce a photographic image until he can 

 produce a perfect visual one. Given a perfect visual image, there are 

 three ways of bringing this to a focus on a photographic film. 



Direct Image Projection ( Figs. 61 and 64 ) . A vertical monocular micro- 

 scope is set up and a camera is lowered over the top. The front of the 

 camera is fitted with a light-tight connector and the top of the camera 



FILM 



GROUND GLASS OR FILM 



FILM 



SWINGING MIRROR 

 DEFLECTS IMAGE 



CAMERA FITS 

 OVER OCULAR 



FOCUSSING 

 OCULAR 



CAMERA REPLACES 

 OCULAR 



PRISM SPLITS 

 IMAGE 



CAMERA IS PART 

 OF MICROSCOPE 



62 



Figs. 61, 62, and 63. Three methods of projecting the image from a microscope onto 

 a film. Fig. 61 is the direct-projection method. The camera fits over the tube of the 

 microscope, in which there is either a regular or a special photographic ocular. Fig. 62. 

 The reflex projection method. A mirror diverts the image into focus on a glass reticle 

 seen on the right. A special eyepiece is focused on this reticle. The picture is taken 

 by swinging the mirror on one side to project the prefocused image onto the film. 

 These cameras fit into the top of the microscope in place of the eyepiece. Fig. 63. 

 Split-beam method of projection. The camera and regular binocular observation eye- 

 pieces are both integral parts of the microscope. The beam is divided between these 

 so that when the visual image is in focus the projected image is also in focus on the film. 



