THE CAMERA 



343 



element or combination of two of the 

 elements of his set. 



Let us see how the Protar combina- 

 tions work out in practice. Say we 

 have a Protar which has as its com- 

 ponents two lenses of focus 13 -\\ inches 

 each. By using the lenses either to- 

 gether or singly, two focal lengths are 

 available. The single lens will make a 

 hill or a distinct building look twice 

 as big as the doublet, a tremendous 

 advantage when you cannot approach 

 nearer to the hill, for it means the same 

 as though you had instantly taken an 

 aeroplane ride and annihilated half the 

 distance of the camera. In practice 

 this would probably mean the middle 

 of a pond or a point over a deep valley, 

 where obviously the camera never 

 could be placed. 



A Protar set is like a card index. 

 You can put it together and rearrange 

 it any time in another order if you care 

 to. Some Protar lenses have dissimi- 

 lar components. This is the same as 

 buying three lenses for the price of one. 

 If your image is not big enough with 

 the lens complete, try the single ele- 

 ment next longer in focus, or if needed, 

 the third. Notice that the camera need 

 not be disturbed during all these 

 changes, which is a great convenience. 

 Many times in photography we find 

 that one and only one viewpoint is per- 

 missible. The man with a Convertible 

 Protar can easily adapt his focal length 

 to any exposure at hand. 



Let us take as an example, two un- 

 equal focus elements of 13)4 and 11 3-16 

 inches focus, making when combined a 

 doublet of focus 7 inches. 



Xow let us suppose a third single 

 combination unlike the others be added. 

 By the law of combinations, we now 

 have three focal lengths in the single 

 elements and we can make three pairs 

 in addition, or six separate and distinct 

 focal lengths are now available. Think 

 of the convenience of having all the 

 lenses usable in the same camera with 

 one shutter, with one flange and one 

 front-board ! 



This set is furnished in case with 

 compartment for each lens. A larger 

 variety has ten available focal lengths. 



Especially useful is the Protar in 



nature work. Suppose now that we 

 wish to photograph a nest on the 

 ground with the eggs or little ones just 

 hatched out. While at first, it would 

 seem wise to photograph at a near 

 point, there are many reasons against 

 this procedure. Our object is to get a 

 correct representation of this nest and 

 its inhabitants in their natural sur- 

 roundings. If we stay near, we photo- 

 graph merely a frightened bird or per- 

 haps we find no bird at all. But the pro- 

 cedure is very easy in such a case ; move 

 back and use a longer focus lens, i. e. 

 a single element. The movement away 

 from the nest removes a source of dis- 

 turbance to the mother bird, but the 

 size of the image is yet the same since 

 a longer focus lens is being employed. 

 The bird is now in its natural pose, and 

 the nervousness being removed, you 

 still find no difficulty in making the 

 longer exposures, as the birds are now 

 fairly quiet. 



The use of a long focus lens means 

 better perspective. The proportion of 

 nest to surroundings is now better ren- 

 dered, the whole effect being more nat- 

 ural. Use a long focus lens when pos- 

 sible and your nature pictures will 

 show a marked improvement. 



The same remarks obtain when pho- 

 tographing flowers. This fascinating 

 branch of photography demands more 

 attention than has heretofore been 

 given. There are some precautions to 

 be observed, one being to use only 

 color-sensitive plates for this work. 



A PHOTOGRAPH BY THE GERMAN MAKE OF 



PRl ITAR F. 6.3. 



By Brown Brothers. 



