344 



THE GUIDE TO NATURE 



A PHOTOGRAPH BY THE AMERICAN MAKE 



OF PROTAR Vila. 



By L. F. Brehmer, Rutland, Vermont. 



The ordinary plate is color-blind and 

 persists in rendering blues as white and 

 reds and yellows as black, all of this 

 can be obviated by the use of a proper 

 plate, sensitive to yellow and green, 

 and in the case of deep red flowers, 

 plates sensitive to all colors (panchro- 

 matic) should be employed. A Ray 

 Filter will further improve results, for 

 the color-sensitive plates, although 

 showing marked sensitiveness to the 

 colors are yet over-sensitive to blue 

 and the ray filter is a further corrector. 

 Perhaps we wish to photograph a 

 deer in his native haunts. The short 

 focus lens will make a quicker expos- 

 ure, it is true, but in order to get a 

 sizable image, we must approach pretty 

 near the animal. This means that we 

 have tremendous difficulties, as the 

 deer is away before we make the pic- 

 ture. "With a single Protar of long 

 focus, we can photograph as big at 200 

 feet as we tried to do at 100 feet with 

 the doublet, and as the animal is at 

 ease and not on the alert for a spring 



into the brush, we shall have a chance 

 i"< 'i- .1 1< mger exposure. 



As wide angle and long focus are 

 opposites we find that when we 

 increase the image size, we decrease 

 the angle of view included, and vice 

 versa. Therefore when we photograph 

 tin camping place in the woods, the 

 double I'rotar and its wider angle is 

 essential. The fortunate possessor of a 

 Protar set can of course have a choice 

 of image scales and angles at will, 

 < le] lending on the units which he pos- 

 sesses. Certainly no lens can offer the 

 variations for the money invested as 

 the Protar set, and the beauty of it is 

 that only two units are necessary at 

 the outset. 



The Protars can be pressed into ser- 

 vice for architectural subjects. As 

 stated before, the single combinations 

 are wonderfully corrected, and are far 

 superior to the half combinations of 

 symmetrical lenses, which must be 

 stopped way down if definition is ex- 

 pected. The advantage of long focus 

 perspective is well known, but we can- 

 not ahvays make use of them in archi- 

 tecture on account of the restrictions 

 of working space. 



It is in the mountainous country that 

 the Protar single elements are of untold 

 advantage. Many a picture you have 

 seen of mountain scenery where the 

 foreground was so prominent that the 

 mountains seemed to show no height 

 at all. Such a picture results when a 

 short focus lens like that on the ordi- 

 nary kodak is used for the purpose. In 

 this case, we use the single element of 

 the Protar and make the mountains 

 prominent. 



Although the single Protar elements 

 have but a speed of F 12.5, they are 

 fast enough for this work, since we 

 will employ them mainly on distance 

 work where the exposure is of neces- 

 sity shorter on account of the blue 

 light which such objects reflect. You 

 have seen the purple cast of a distant 

 landscape in nature, and noticed the 

 rendering of it on the painter's canvas. 

 Knowing that a photographic plate is 

 the most sensitive to blue, we make 

 allowance for it in shortening the 

 exposure. 



