LOW-POWER PHOTOMICROGRAPHY 



129 



is the most convenient, as exposures can be made by 

 switching it on and off. There are several arrangements 

 of this k'.,d on the market, among which Lancaster's 

 Ellipsoid Enlargers may be mentioned ; in these the 

 reflectors are of matt opal glass and the lamps are placed 

 at the top of the lantern instead of at the side. 



The camera must be clamped to the table or baseboard 

 to give it the necessary rigidity, and its front should be 



Fig. 41 



CAMERA FOR PHOTOGRAPHY OF INSECTS 



fitted with a lens board and flange, with the R.M.S. 

 thread, or arranged to carry an adapter into which the 

 small lenses can be screwed. A time and instantaneous 

 shutter is a great convenience when it can be fitted. 



A focussing movement at the lens or camera front 

 may be very difficult to manage on account of the length 

 of bellows, and because the lens has to be very often 

 between the lamps or beyond them. These difficulties 

 can be got over in several ways. The bellows can be made 



