These spectral transmittance data are based on the
measurement of a single filter of each type. Filters from other production
batches may differ in their spectral properties, specially for wavelengths
outside the range described in the manufacturer's published specifications.
The characteristics of some types of glass filters may change with time
through surface oxidation or by effect of exposure to radiation including
solar radiation. The data provided is to be used only as a coarse guide.
When filter properties are important the filter actually used should be
measured.