92 NEBRASKA ORNITHOLOGISTS' UNION 



much better result. There is usually a great contrast between the 

 color of the eggs and the material composing the nest, which renders 

 it necessary to overexpose upon the eggs in order to get the desired 

 detail of the nest. Always expose for the nest, nevertheless, and cor- 

 rect the overexposure in development. The use of a ray screen (of 

 picric-acid-yellow color) will reduce this overexposure, and will also 

 bring out the delicate lilac mai-kings found ujion some eggs. When 

 using a screen or ray filter the exposure must be increased four to 

 eight times its usual period. 



A freqiient error of beginners is that they try to get the picture too 

 large for the size of their i^late. It is usually best not to fill the plate 

 with the image of the nest. Get a little of the surroundings, so that 

 your photograph will tell its own story as regards site, kind of bush, 

 etc., and you will be better pleased after you have made a print from 

 the negative. Focus upon the nest from different locations and dis- 

 tances, and select the one that shows the best image on the ground 

 glass after several trials. Look at this through a blue glass to secure 

 the monochromatic effect of a print, and you can judge better. Tnke 

 plenty of time to focus carefully, and if there is no wind to swing the 

 nest, stop the lens down and prolong the exposure, in order to get 

 perfection of detail. I frequently stop down to 64 and sometimes to 

 256, and expose from one-half minute to three minutes, where 1 could 

 make an equivalent exposure in one-fifth of a second with lens work- 

 ing at full aperture. After exposing the plates and replacing the twigs 

 bent aside, it is well to retire to some distance as soon as possible, so 

 as to cause the birds as little alarm as you can. 



If after exposing all your plates yoxi should find some especially 

 desirable subject, look up your notes (which should always mention 

 subject, plate, time of day. condition of light, and length of exposure) 

 and see if you have a plate that is probably underexposed, or more so 

 than any of the others. Expose this plate upon your latest find, giving 

 five to six times the normal coeposttre, and when you develop it use a solu- 

 tion strong in reducing agent and bromide and weak in alkali. With 

 proper care a negative thus produced will yield good j)rints after it has 

 been intensified. The first exposure will be "lost in the shutfie." 



The great majority of bird snapshots are underexposed, and unless 

 properly developed will yield poor negatives, whose resulting prints- 

 will look like "chalk and charcoal." Although much has been said and 

 written about the development of snapshots and underexposures, I 

 feel justified in adding a few hints. Forcing development of underex- 

 posures is a fallacy; a bad theory which has spoiled more negatives 

 than all other methods of development combined. The majority of 

 photographers try to "force up" an underexposure by using a de- 

 veloper that is too aggressive— too strong in reducing agent. The 

 best and safest rule to follow is: The greater the underexposure, 

 the weaker the developer and the longer the period of development. I 



