• Johnson standard UBVRI,
• three of the Wing 8-color filter set, and
• the Strömgren uvby four-color set.

A Clear glass filter of BK-7 and the Hß wide and narrow band filter sets are also available in ½" diameter sizes. Each of these filters can be factory mounted directly into the 2, 6 and 10-position filter sliders of the SSP series photometers and also into the 8-position filter wheels of the new Optec SSP-7 High Precision Photometer.

For CCD users interested in larger filter sizes, Optec has developed 1" (25.4mm) diameter filters mounted in 1¼" filter holders threaded for eyepieces and filter wheels manufactured by SBIG and other companies. These filters can be transformed to the Johnson or Kron/Cousins/Bessell systems when used with CCD detectors. For a brief discussion of the Johnson and Cousins/Bessell broadband filter systems, see the paper written by Gerald Persha, President of Optec entitled Johnson vs. Cousins/Bessell Filter Standards, or download the pdf version of this paper.

The use of the Optec filters with CCD detectors is described more fully in the document Model PFE-1 Photometric "Front-End" CCD/Telescope Adapter Technical Manual. This document is available for download in Adobe PDF format from Company Seven's Optec file library.

As part of our Optec MAXfilter 2" Automatic Filter Selector product we also offer 50mm photometric filters for insertion into our 3-position filter sliders. These Johnson/Cousins filters are made to the Bessell specifications.

Refer to the following table to determine which filter should be used for an application.

Optec Stock No.	Filter Type and Instrument Detector	Filter Size
17031	Johnson U filter, silicon photodiode or CCD	12.5mm diameter
17032	Johnson B filter, silicon photodiode or CCD	12.5mm diameter
17033	Johnson V filter, silicon photodiode or CCD	12.5mm diameter
17034	Johnson R filter, silicon photodiode or CCD	12.5mm diameter
17035	Johnson I filter, silicon photodiode or CCD	12.5mm diameter
17036	Clear filter, any detector	12.5mm diameter
17037	Wing MA filter, 712nm, any red/IR sensitive detector	12.5mm diameter
17038	Wing MB filter, 754nm, any red/IR sensitive detector	12.5mm diameter
17039	Wing MI filter,1025nm, any red/IR sensitive detector	12.5mm diameter
17041	Johnson U filter, S-5 response PMT	12.5mm diameter
17042	Johnson B filter, S-5 response PMT	12.5mm diameter
17043	Johnson V filter, S-5 response PMT	12.5mm diameter
17045	Stromgren u filter, any detector	12.5mm diameter
17046	Stromgren v filter, any detector	12.5mm diameter
17047	Stromgren b filter, any detector	12.5mm diameter
17048	Stromgren y filter, any detector	12.5mm diameter
17049	Hb narrow & wide filter set, any detector	12.5mm diameter
17132	Johnson B filter, silicon photodiode or CCD [View transmission curve]	25.4mm diameter
17133	Johnson V filter, silicon photodiode or CCD [View transmission curve]	25.4mm diameter
17134	Johnson R filter, silicon photodiode or CCD [View transmission curve]	25.4mm diameter
17135	Johnson I filter, silicon photodiode or CCD [View transmission curve]	25.4mm diameter
17446	Cousins B filter (Bessell specifications for CCD) [View transmission curve]	50mm diameter
17447	Cousins V filter (Bessell specifications for CCD) [View transmission curve]	50mm diameter
17448	Cousins R filter (Bessell specifications for CCD) [View transmission curve]	50mm diameter
17449	Cousins I filter (Bessell specifications for CCD) [View transmission curve]	50mm diameter

Consult our current Astronomical Filter Price List for the filters listed above. Please note the stock number of the required filter.

Optec also supplies Tri-color RGB color separation filter sets and general purpose filters for use with the MAXfield telecompressor and MAXfilter 2" Automatic Filter Selector systems.