BS ISO 10505:2009 Photography. Root mean square granularity of photographic films. Method of measurement
BS ISO 10505 describes a method for determining the intrinsic root mean square granularity (rms-granularity) of photographic films. Intrinsic rms-granularity refers to those density fluctuations produced solely by the distribution of developed image forming centres in the photographic emulsion.
Continuous-tone monochrome (silver absorbing species) and colour (dye absorbing species) materials coated on a transmitting support can be measured by the procedures described in BS ISO 10505.
BS ISO 10505 is intended for imaging systems with viewing magnifications between 5× and 12×.
The following kinds of granularity measurements are not covered by BS ISO 10505, even though they are photographically important:
Reflecting materials (photographic papers)
Materials having emulsion coated on both sides of the support (e.g. some X-ray films)
The estimation of the noise power spectrum (Wiener spectrum).
Contents of BS ISO 10505:
- Foreword
- Introduction
- Scope
- Normative references
- Terms and definitions
- Measurement instrument
- General
- Microdensitometer
- Spectral products
- Spatial frequency response
- Scanning motion
- Instrument electronics
- Conversion to density
- Temporal frequency response of the instrument
- Instrument noise
- Diffuse rms-granularity
- Optical geometry
- Diffuse conversion factor g
- Preparation of specimens
- Sampling and storage
- Exposure
- Processing
- Specimen uniformity
- Sampled area
- Operation of the measurement instrument
- Positioning the specimen
- Specimen scanning
- Control of focus
- Rate of scan
- Density mode
- Method of test
- Principle
- Statistical background
- Construction of the median estimator and the 95 % confidence intervals
- Instrument noise
- Diffuse rms-granularity
- Uncertainty of the rms-granularity result
- Reporting results
- Summary of rms-granularity characterization parameters
- Typical viewing magnifications for critical naked-eye viewing
- Limiting the temporal frequency response of the measuring instrument
- The effects of specimen non-uniformity
- Derived constants c for subgroup sizes 10, 20, …, 200
- Determination of sample size for specified precision and subgroup size
- Bibliography