Cameras, Lenses, and Shutters 43 



from those that cost less than a dollar and are 

 put in the very cheapest of cameras, to those 

 that cost up in the hundreds. If we can afford 

 it, it is well to have more than one lens, even 

 though we are doing all our work on the same 

 size plate with the same camera. We should 

 have one lens that will work very rapidly, for use 

 where we are willing to sacrifice depth of field and 

 focal length to speed. We should have another 

 for use where depth of field and focal length are 

 necessary ; and we should, without question, have 

 a telephoto, of which I shall speak at length in 

 another chapter. 



It is always a good plan, when buying a lens, 

 to get one that is made to cover a plate one size 

 larger than the one we intend to use, as by so 

 doing we acquire greater focal length and greater 

 illumination of the plate, which necessarily gives 

 greater speed than will the same style of lens one 

 size smaller. 



An anastigmatic lens is always preferable to the 

 cheaper rapid rectilinear. The advantages of the 

 former over the latter are : rapidity, extremely 

 fine definition over a very large flat field at a 

 large aperture, portability, and freedom from as- 

 tigmatism. The great covering power of the 

 anastigmat is an immense advantage alone. The 

 front of the camera may be raised to any extent 

 that the camera will allow, without fear of leaving 



