ve to the 
vith light 
spectral 
ıtion and 
ographed 
) in each 
field. 
e test. If 
vith each. 
1e report. 
indexing 
for which 
For full 
\pertures, 
3S. 
n service. 
with dif- 
quivalent 
s a plane 
t the time 
ilm plane 
tolerance. 
should be 
at the 
  
a is not a 
| used and 
squivalent 
t used in 
luced. 
t sym- 
may be 
  
2.11 
2.12 
2.13 
2.13.1 
2.13.2 
2.13.3 
2.14 
2.14.1 
2.14.2 
2.14.4 
2.14.7 
DN 
.14.8 
2.14.9 
2.14.10 
Processing 
Processing of the service emulsion shall be equivalent to that used in prac- 
tice. An alternative emulsion permitted under section 2.9.1 shall be processed to 
give the equivalent results required there. Care shall be taken to avoid conditions 
which would produce strains in the emulsion. 
Measurements 
Measurements shall be made in a way which permits all tangential measured 
distortions to be based on a single reference system. 
Shape of Locating Surfaces for Films or Plates 
The departure of the film or plate locating surfaces from flatness, or from 
some other intended shape, shall be determined. 
These departures shall be computed with reference to an ideal plane (or other 
intended surface) so positioned as to fit the real surface well and to make the 
maximum value of absolute departure as small as possible by making the 
numerically largest positive and negative departures equal in absolute value. The 
positive direction shall be away from the lens. 
When a locating surface is in the magazine, all magazines to be used with the 
camera shall be tested. 
Presentation of Results 
The report should give at least the following data: 
The location of the principal point of autocollimation with respect to the 
fiducial centre. *) 
Calibrated principal distance, or calibrated focal length, with criterion used 
to establish it. 
Curves (with plotting points shown) or a table of radial measured distortion, 
having as its origin the principal point of autocollimation as defined in section 
2.2.3, along each of the four semi-diagonals and of the average of these four sets 
of values. *) 
A statement of the maximum difference between radial measured distortion 
and average radial measured distortion at any field angle. *) 
A statement of the maximum value of tangential measured distortion based 
on the reference frame which makes this a minimum by making maximum values 
of opposite sign equal in magnitude. 
Distances between opposite pairs of fiducial marks, and the angle between the 
fiducial axes. The precise points involved should be thoroughly identified. 
The maximum departures (-) of the film locating surfaces from their cor- 
rect shapes, or more complete information if required. 
If requested, a table giving the radial and tangential measured distortion 
at each point measured, and/or a statement of the orientation of the line through 
the principal point along which tangential measured distortion is calculated to be 
a maximum. 
A statement of the accuracies of all the information provided. 
*) If radial distortion relative to the principal point of best symmetry is also 
reported it should be clearly named and the position of the principal point of best 
symmetry should be given with respect to the fiducial centre.