AND TREES 7 



flower photography, outdoors and indoors. The reason 

 is largely concerned with the greater depth of focus avail- 

 able at a given opening, and there are other advantages 

 which will appear as the subject develops. A Zeiss 

 Series IV, a Morrison Wide-Angle — any good lens of 

 not over 6^ or 7 inches focus for a 5 x 7 plate — will do 

 good service. Of course there are special conditions 

 which will require the use of a lens of longer focus ; and 

 if the wide-angle lens selected is either symmetrical or 

 "convertible," one of its elements will sometimes prove 

 very serviceable. One thing is worth attention in choos- 

 ing a lens for flower photography. Get one with an iris 

 diaphragm, in which the diaphragm opens up to the full 

 diameter of the lens. This is of great service in focusing, 

 enabling the correct focus to be obtained far more quickly 

 and avoiding the eye-strain which will be felt if one has 

 to grope around on the ground-glass for an image focused 

 indoors at ffxi or smaller. 



Any good tripod will do, of course, but for indoor work 

 some form of camera stand which can be readily shifted 

 in a horizontal plane is far more serviceable than any 

 tripod. Visions of vexation cross the writer's mind when 

 he remembers the many times he has kicked his tripod 

 out of a laboriously obtained position while preparing 

 for exposure on fast wilting flowers ! A regular studio 

 camera stand is excellent for indoor work, or a stand may 

 be improvised with boxes and a small table, the camera 

 taking its place on top, unfastened. The special form of 

 camera stand and exposing frame combined, described 

 on page 14, is superior for this work, and the earnest 

 operator will probably provide himself with this stand 

 or some equivalent apparatus. 



Orthochromatic plates are far better for 

 Plates. flower photography than plain plates, 

 because most flowers have some shades 

 of yellow, and all green foliage is better rendered with 

 them. A ray-filter is not an advantage save for deep 

 orange and for blue shades, for with the best rapid 

 isochromatic plates, in themselves quite sensitive to yel- 

 low and slightly repellant to blue, the additional restraint 

 of even a much diluted bichromate cell vvill over empha- 

 size the yellow shades, giving even a bright canary the 

 same density on the plate as pure white. If blue flowers 

 are to be pictured, however, the ray-filter becomes essen- 

 tial. A §lass cell, filled with a i per cent, solution of po- 

 tassium bichromate, 10 parts to 1,000 parts, will be found 

 satisfactory. The ray-filter sent out by the Bausch & 

 Lomb Optical Co. is now filled with this standard solution. 



