THE PHOTOGRAPHY OF COLOUR 



By CHAPMAN JONES, F.I.C., F.C.S., etc. 



Royal College of Science, London 



I 



As this problem has engaged the attention of innumerable 

 workers for nearly a hundred years, and the best methods so 

 far known are now carried out on a considerable scale, it is 

 obviously impossible to deal with the subject with any approach 

 to completeness within the compass of an article such as this. 

 I propose, therefore, to consider the principles involved rather 

 than the practical details, and to deal with the subject broadly 

 rather than minutely. 



It is worth while first to ask, What is meant by the expres- 

 sion "photography of colour"? There is no doubt whatever 

 as to what it means in its simplest conception. Ordinary 

 photography depicts form with an accuracy and minuteness 

 that far exceeds the best handwork ; and by special care — that 

 is, the use of special lenses and of cameras made after the 

 manner of surveying instruments — it is possible to get results 

 that may be depended upon for surveying purposes. Not only 

 is correct "drawing" inherent in photography, but also the 

 rendering of light and shade — that is, the comparative luminosi- 

 ties of the various parts of the object, within certain limits that 

 are well understood. The simplest idea and the most acceptable 

 method of the photography of colour is that in which the colour 

 of the object is reproduced as automatically and correctly as its 

 shape, and shall be visible on ordinary inspection as the colours 

 of a painting are. Such colour photography has been eagerly 

 sought for but is as yet impossible ; and if one is justified in 

 judging of the future in the light of the past, it will remain 

 impossible. There does not seem any line of work that can 

 lead to such a result. From this point of view colour photo- 

 graphy as now practised is always a compromise. 



The methods of both the past and the present naturally 



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