Optec offers a wide selection of filters for astronomical photometry in standard color systems. These filters are designed for the SSP series of single-channel stellar photometers and are 12.5mm (.5") in diameter and 7.00 mm thick. The filter sets offered are the Johnson U B V R I J H wide-band standard color set, StrÃ¶mgren u v b y medium-band four-color set and the HÃŸ wide & narrow band filter set. Each of these filters can be factory mounted directly into the 2 and 6-position (automatic) filter sliders for the SSP photometers.
For routine photometry, consider a B - V set mounted in a two position slider. Consult texts on astronomical photometry for more information on the use of these special filters.