INTRODUCTORY. 7 



using the camera only as an aid to their hobby 

 for accurately recording their observations. This 

 surely is photography fittingly applied. For ac- 

 curacy and minuteness of detail, as well as for 

 rapidity of execution, it must stand alone, quite 

 unassailed by the art of brush or pencil. Nor 

 is its least attribute its absolute trustworthiness 

 and inability to err. We may wrongly interpret 

 the image it gives us through mis judgment of 

 perspective or any other cause, but then the fault 

 is with us and not the lens. A camera, fortunately, 

 cannot think or discriminate : its method is entirely 

 mechanical. We are prone to find it wrong in 

 matters of colour rendering, but of course such 

 apparent error arises from the fact that the plate 

 and man are not equally sensitive to the same range 

 of light ; but that does not make the one wrong 

 because it is insensitive to red, any more than it 

 does the other for being inert to ultra-voilet rays. 

 It is all a matter of standpoint. 



Orthochromatic Plates. 



But since there is at our disposal a variet}^ of 

 differently sensitive plates, it is only wise to select 

 such as are in " colour- tune " nearest to our own 

 standpoint, for thereby will things be represented 

 more nearly as they appear to us. It is with this 

 object that the manufacturers have placed upon 



