VISION AND THE TECHNIQUE OF ART. 41 



In such a picture, all objects not at the center of interest would be 

 painted so that, when the center of interest in the picture was looked 

 at, the picture as a whole would make an impression similar to that 

 produced by the scene itself. Such pictures as photographs taken with 

 corrected lenses attempt to do this but, as has been stated, fail in that 

 they do not give a proper suggestion of depth. 



In this third type this deficiency might be met by accentuating the 

 characteristic imaging of all objects not at the focus point to suggest 

 their position in tri-dimensional space. For instance, near dark 

 objects, in the line of focus, would be shown with red edges, distant 

 ones with blue; and, on the sides of the picture, the radial accentuation 

 of distant objects and the tangential accentuation of near objects 

 would be shown. 



In making these peripheral accentuations it would have to be borne 

 in mind that they would be modified by the oblique aberrations of the 

 eye as they would lie on the peripheral part of the picture and be 

 imaged on the periphery of the retina. Allowances would therefore 

 have to be made. As the picture plane lies near the secondary 

 astigmatic field the radial accentuations would have to be relatively 

 slight and tangential accentuations relatively marked. No distortion 

 would be put in such a picture as the eye itself would introduce it, if 

 the picture was viewed from the proper distance. 



Granting that the proper accentuation of the radial and tangential 

 and chromatic edges could be made, which would be very difficult, it is 

 questioned whether such a picture would be satisfactory. 



The proper impression could only be produced when the center of 

 interest of the picture was looked at. If any other part of the picture 

 was looked at that part would not only appear like nothing ever seen 

 before but the rest of the picture would then cease to produce the 

 proper impression. 



THE RETINAL PICTURES AND ARTISTIC PHOTOGRAPHY. 



As has been stated cameras in their inception were copied after the 

 eye. It can be argued that the value of photographs for pictorial 

 purposes rests on two quite different bases. One that it lies in repro- 

 ducing in black and white, or in photographs in color, the same general 

 picture we get on our retina. The other that it lies in reproducing in 

 light and shade detail and color the effects that exist in nature. 



On the first basis it can be said that the results, when looked at, are 

 satisfactory because they appear to us similar to the impression we 



