214 Mr. A. Claudet on the Optics of Photography. 



matical truth which is inherent to the action of the most perfect 

 lenses, and which is particularly observable in the part of the 

 image situated in the plane of the exact focus of the lens. 



Convinced myself of the advantage which, in an artistical point 

 of view, would result from photographic portraits being taken in 

 such a manner that they should as much as possible resemble a 

 work of art, in which all the features are marked by light touches 

 of the brush or pencil, softly blending from light to shade, such 

 an important subject has for a long time occupied my attention. 

 My precise object has been to discover a method of removing, if 

 possible, from photographic portraiture that mechanical harsh- 

 ness which is due to the action of the most perfect lenses. 



In the best works of art all the effects are produced by a soft 

 and harmonious treatment; nothing is hard or dry, nothing is 

 too minutely delineated : in fact the hand of the artist is not 

 capable of microscopic correctness — and fortunately so, for its 

 work is not intended to be examined by a magnifying lens; still 

 the general effect may be sufficiently minute for the artistic 

 purpose. 



Notwithstanding its defects, photography is the great teacher 

 to artists : they find in it the true reflex of nature ; it shows the 

 correct distribution of light and shade with all its delicate half 

 tints; its perspective drawings are perfect, and it represents the 

 folds and texture of draperies in the most exquisite manner. 

 But if art derives a great advantage from the imitation of photo- 

 graphic productions, art is in its turn a very competent and va- 

 luable teacher of photographers. Their works indeed have no 

 value if they do not partake of a certain character which distin- 

 guishes the best works of art. And therefore photographers 

 must not despise the recommendations of true artists ; for in try- 

 ing to imitate art they will often improve their own productions. 

 Therefore as artists have nothing better to do than to imitate 

 photography, so photography has nothing better to do than to 

 be guided by art. 



By the laws which regulate the action of lenses, it happens, as 

 has been already pointed out, that in the representation of a solid 

 figure there is strictly only one plane of that solid which can be 

 taken in perfect focus. The image therefore of that plane is 

 not in harmony with the images of the other planes, which are 

 not so sharply defined. This inequality in the texture of the 

 image cannot but be considered a defect ; and it would be a great 

 advantage if it were possible to equalize the effect, even at the 

 cost of losing the mathematical accuracy of the plane in focus. 

 I hope to show indeed that such a loss would be really a consi- 

 derable gain. If photographic portraits should not exhibit all 

 the pores, wrinkles, and defects of the skin, it is still less desi- 



