42 AMES, PROCTOR AND AMES. 



have received. On the second basis it can be said they are satis- 

 factory because in looking at them our eye is affected in the same way 

 as it is affected by nature. 



In spite of the inherent impossibility already pointed out that the 

 effect of objects in tridimensional space cannot be reproduced on a 

 flat surface, it seems to have been the second basis that was followed 

 in the evolution of the art of photography. This led to the develop- 

 ment of corrected lenses which would image everything in the field of 

 view in full detail with no distortion. 



After such lenses had been perfected it was found that the photo- 

 graphs taken with them, although ha"ring unquestioned value for 

 scientific and other purposes, were not satisfactory from an artistic 

 point of view. 



Then followed the use of so called "soft focus" lenses, and various 

 manipulations in printing and enlarging to get away from the hard full 

 detail effect produced by corrected lenses. Those desiring artistic 

 effects bought up old lenses such as were used in making daguerreo- 

 types and had lenses designed in which various aberrations were left 

 uncorrected. As a result there has of late years been a most marked 

 advance in the artistic side of photography. 



The method of development has however been one of "cut and try" 

 and as far as is known, with the exception of the work done by Gleichen 

 mentioned above, no fundamental laws have been followed. In- 

 numerable methods and lenses have been tried and only those pro- 

 ducing pleasing effects have survived. 



It is believed that the advance in artistic effect has been due to the 

 fact that the results obtained were more similar to the subjective im- 

 pression and that future developments in photography on the artistic 

 side will come from approximating as closely as possible the retinal 

 pictures and mental visual images. 



THE RETINAL PICTURES AS THE BASIS OF THE TECHNIQUE 



OF ART. 



In the chapters describing the characteristics of retinal images of 

 objects situated in different parts of the field of view examples were 

 given of paintings by artists in which these characteristics appear. 

 The lists do not mention a far greater number of works that are in 

 general suggestive of the retinal picture without showing the special 

 characteristics noted. Of these Corot is the best example. Whistler, 

 Manchini and Abbot Thayer and many others are also examples. 



