This section is from the book "Aerial Cameras, Aerial Films, And Film Processing", by Richard W. Underwood.
Before one can do any type of accurate work with an aerial camera, comprehensive knowledge of its calibration is mandatory. If you cannot secure the information from a reliable source or by means of measurements with your own laboratory equipment, you must consider the calibration an unknown factor and proceed accordingly.
You cannot tolerate unknown factors that might affect the accuracy or precision of your work. Therefore, do not attempt to make scientific deductions based on unknown or erroneous camera calibration information. You must know your camera thoroughly, including accurate knowledge of:
• radial lens distortion
• tangential lens distortion
• calibrated focal length
• transmission characteristics
• spectral characteristics
• resolution of lens
• flatness of focal plane with respect to optical axis
• accuracy of exposure at all shutter settings
• position of reseau markings and all other fiducial marks
• accuracy of any built-in accessories such as clocks, frame counters, altimeters, vacuum gages, data recorders, intervalometers, etc.