February, '17] WALDEN: INSECT PHOTOGRAPHY 27 



About 85 per cent of our laboratory photographs are either natural 

 size or twice enlarged. A 5 x 7 box camera has been built to meet 

 these requirements (PI. 1, fig. 3). It consists of three sections built 

 of one-half-inch wood and mounted on a baseboard which fastens to 

 the sliding bed of the stand. The front section is firmly fastened to 

 the baseboard and takes the regular lens board of the 5x7 view camera. 

 The rear section slides up and down on the bed, and is fitted with a 

 back from a regular camera. These two sections fasten together and 

 with the 4|-inch lens form a fixed focus camera for photographing 

 natural size. A third section 4| inches long can be inserted between 

 the other two sections, thus making the camera of the right length for 

 photographing twice natural size (PI. 1, fig. 4). The object can be 

 centered by sliding the ground glass support back and forth in one 

 direction and by moving the lens, which is mounted on a sliding lens 

 board, in the other direction. This camera is absolutely rigid and is 

 very simple and convenient to operate. The 48 mm. lens can be used 

 to give the desired magnifications by means of extensions fitted in 

 place of the regular lens board. 



Field Outfits. — The department has three outfits for field work, 

 a 5 X 7 camera with a triple entension, a 4 x 5 long bellows camera, 

 and a 3j x 4j roll film camera. These cameras are all fitted with 

 anastigmat lenses and good shutters. In addition to these, three 

 members of the department have small high grade 2j x 3| cameras, 

 which are very useful in field work. In fact, with the outfits men- 

 tioned above, their usefulness apparently increases as their size de- 

 creases. The small cameras are readily carried in the pocket, and 

 are simple and inexpensive to operate. The high grade lenses, being of 

 short focus, give sharp, clean negatives of good depth, which are 

 capable of being enlarged to 8 x 10 or even to 11 x 14 inches. One of 

 the most important features of these cameras is the fact that the 

 negatives are just the right size for making lantern slides by contact. 



In our 1915 report eight of the eleven illustrations showing field 

 views were made from these 2j x 3j negatives. 



Though the writer would not go so far as to recommend this size 

 for all field work, he considers that the most useful size for a field outfit 

 would be a compact plate camera, not larger than SJ x 4j, with a long 

 extension and fitted with a convertible anastigmat lens and a good 

 shutter. 



It is frequently necessary to make photographs in the field looking 

 directly down on the ground. This can be accomplished by making a 

 right-angled bracket of two pieces of board with a tripod socket in 

 each; the horizontal part is fastened to the head of the tripod and 

 should project far enough beyond the head to clear the tripod legs. 



