Photometric photography. I - The multiple-filter method for characteristic curve measurement
Abstract
A simple method for determining the calibrated response function for a photographic film is presented; it is called the multiple-filter method. The measurement is defined by two or more images made of the same scene with differing attenuations, i.e., different aperture settings. With known attenuations between the images, the photographic response function (characteristic curve) can be reconstructed from these images over the range of intensity available in the scene. A method for this reconstruction is presented. The method shows an accuracy of 0.2 millidensity (about 0.00005 intensity) in certain limits of applicability in numerical simulations. Tests made of actual photographic samples give internal consistency in their solutions to about 8 millidensities rms (about 0.002). The photographic tests are limited by granularity, development uniformity, and defect noise in the samples.
- Publication:
-
Journal of the Optical Society of America A
- Pub Date:
- 1988
- DOI:
- 10.1364/JOSAA.5.000351
- Bibcode:
- 1988JOSAA...5..351N
- Keywords:
-
- Computerized Simulation;
- Image Filters;
- Image Reconstruction;
- Photographic Film;
- Visual Photometry;
- Calibrating;
- Curves;
- Nonlinear Optics;
- Truncation Errors;
- Instrumentation and Photography