Distances between opposite pairs of fiducial marks, and the angle 
between the fiducial axes. The precise points involved should be thor 
oughly identified. 
The maximum departure (±) of the film locating surface from its 
correct shape, or more complete information if required. 
If requested, a table giving the radial and tangential image displa 
cement at each point measured. 
A statement of the accuracies of all the information provided. 
Veiling Glare. 
Veiling glare shall be measured in the following manner or by a 
method from which equivalent results can be obtained. 
Test Field. 
The test field shall be equivalent to an infinite uniformly bright 
Lambert’s Law surface containing a perfectly black spot. The black 
spot shall be circular and its diameter shall subtend an angle of 1° ± 5' 
at the lens of the camera. The illuminant shall be that of Section 1.4. 
There shall be no substance other than air between the test field and 
the lens or its attached filter. The black spot shall be at such a distance 
that the black centre of its out of focus image in the film plane of the 
camera is at least 1 mm in diameter. 
Photometry. 
The camera shall be used to photograph this test field on the 
usual aerial emulsion held in the camera’s entire film plane in the usual 
manner. Well controlled method of photographic photometry shall 
be used to obtain the illumination of the centre of the image of the 
black spot and the average illumination 1° 30' from it in the image of 
the bright field. 
note: Light scattered back into the camera by the emulsion can 
contribute significantly to veiling glare. Hence, any test method 
must provide a reflecting surface similar to unexposed film over 
practically the entire film plane. 
Field Angles. 
The above measurements shall be made with the black spot on 
axis and at several other positions in the field, including positions near 
the edges and corners of the field. Any areas which might be affected 
by reflections from asymmetrical structures in the camera shall be 
investigated. 
Apertures 
Measurements shall be made at full aperture and at any other 
desired apertures. The apertures used shall be specified in the report. 
For full characterization of a type of camera tests shall be made at 
three or more apertures.