® off 
icial Circular © 
#20, Revised 
page 2 
progress of his work, as well as for the special 
ends of his Department. 
It is not expected that any films will be 
used on the journey to Cuzco or in Cuzeo itself, 
except 2s directed, but that they will be re- 
served for use in the field as above indicated, 
It is not expected that films will be used for 
landscapes, or for objects properly connected 
with other departments, except as requested by 
the Dierctor, or in cases where it-is known to 
the member that it is probable that he is the 
only member of the Expedition who will have an 
opportunity to get the picture in question, 
IMPORTANT 
Always use a tripod and the Exposure index 
found in the back of the red Burroughs Wellcome 
photographic record book, Snapshots are not 
desired. If a picture is not worth the trouble 
of setting up the tripod, levelling it, and get 
ting the exposure exactly right, it is generally 
not worth taking. Pictures shoud be developed 
4$ 800n as possible after exposure. In no case 
should there be a delay of more than three weeks, 
it is particularly important to go slow at first, 
nd develop each voll as it is taken,until the 
operator becomes @ntirely familiar with the 
atmospheric conditions, the use of the exposure 
meter, and the peculiarities of his eamera, In 
taking pictures at close range, remember that 
the finder is misleading, end that the camera 
must be pointed direatly at the object even 
Ga bb i brings the image out of the center 
of the finder, Learn to estimate distances 
x) Official Circular 9 
#20, Revised 
pare 3. 
accurately, as the exactness of the focus makes 
a great difference in the ultimate utility of 
the picture. Make your records immediately 
after taking the picture, Postponement means 
inability to get exact records, It frequently 
happens that the exact observation of the time 
when the picture was taken is a great help in 
settling doubtful points long after the field 
has been left, The pocket levels which are 
furnished! each member of the Expedition are in- 
tended to! be used in photographic work, as the 
levels on the cameras are not reliable and 
frequently are misleading. The more painstaking 
she process of setting up the tripod, levelling 
the camera, using a small diaphrégm, an accurate 
time exposure, and exact records of the time, 
place, and subject, the better the results of 
the Expedition will be. No time is better spent 
than that in studying your negatives after they 
have been develoved and dried, with the record 
book in hand, seeing whether you got what you 
desired, whethor the exposure was too much or 
too Little, and whether the camera is working 
according to your expectations. Careless and 
hasty work in photography means waste of time, 
loss of opportunities, and poor results. 
be particularly careful to master the de- 
fails of taking and developing pictures according 
to the directions before taking and developing 
any pictures in the field, 
Ask the Quartermaster to issue to you 6. 
exposure films for the beginning of your work, 
so that if there is anything wrong with your 
methods of exposure you will have an opportunity 
to test your work inthe field before you have 
taken more than six pictures, 

