Interference filter calibration for vision research.
The radiant flux (F) transmitted by bandpass interference filters of similar type is approximately proportional to the product of peak transmittance (tp) and half-height bandwidth (Wh). A study of 297 filters of varied design (1-, 2-, 3-cavity), the collections of six vision laboratories, showed that this relation was not accurate across all filters. However, a simple function, incorporating Wh and another bandwidth Wi at a lower transmittance t, predicts F with a precision that is ample (+/- 5%) for most psychophysical research. This function provides a rapid means of calibration. Bandwidth errors caused by 2- and 3-cavity filters are discussed as well as their luminous 'blocking' efficacy.
Moreland
J D
JD
Department of Communication and Neuroscience, Keele University, Staffordshire, UK. coa09@keele.ac.uk
D002138:Calibration; D003118:Color Perception / Q000502:physiology*; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D008433:Mathematics; D011601:Psychophysics / Q000295:instrumentation*; D012684:Sensory Thresholds; D013053:Spectrophotometry