February, '12] PHOTOGRAPHING INSECTS, DISCUSSION 59 



especially for half-tone reproduction are made on a developing paper, 

 such as Velox or Azo. Ever since these papers were first introduced the 

 claim has been made that they are inferior for half-tone reproduction 

 to the older process of printing-out papers, such as Solio. To test 

 the matter, the writer selected a lot of negatives and made a duplicate 

 set of prints, one set on Velox and one on Solio. These were submitted 

 to the head photographer of a large engraving establishment, who 

 was invited to select the print in each case that would make the best 

 half-tone. In most cases the man declared that there was no reason- 

 able preference. A few were decided in favor of the Solio, and some 

 in favor of the Velox. The matter seemed to resolve itself thus. 

 The developing papers have been improved since they were first 

 devised until for many negatives they quite equal the printing- 

 out papers. Their management is so easy and speedy that one does 

 not hesitate to make additional prints from a given negative when the 

 first one seems at all capable of any improvement, and thus a good set 

 of prints is apt to be secured. The printing-out paper, on the other 

 hand, will hold more detail in the very thin and the very dense portions 

 of a negative than can be held with the developing paper. 



Unless, however, the half-tone is to be of fine screen, and printed 

 on good paper, the minute additional detail will likely be lost ; and in 

 that event the well-executed Velox print may give a better effect than 

 the Solio. 



In the case of any print showing an insect at magnifications of 

 three or more diameters, the writer thoroughly believes in the scheme 

 of making a small print showing the insect's natural size, and placing 

 this adjacent to the enlargement. It conveys a better idea of the 

 true appearance of the actual insect than any hair-line can do, and is 

 vastly better than dependence on a legend beneath saying "greatly 

 enlarged" or "x 5." 



President F. L. Washburn: Any discussion on this paper? 



W. H. Goodwin: As an introduction I will say that I have been 

 experimenting with photomicrographic work for four years and have 

 done considerable photographic work for almost fifteen years. I 

 would like to add a few points to Mr. O'Kane's paper on photographing 

 insects. 



In photography, especially when using the ordinary plates, blue in 

 every case photographs much lighter in color than it appears to the 

 eye, while the reds in a photograph appear as black and much darker 

 than one would expect. Isochromatic or preferably orthochromatic 

 plates have dyes incorporated in the emulsion which make them less 



