Filter

Astrodon Photometrics Johnson-Cousins Filters

Spectral profiles designed after UV, B, V, Rc, Ic Johnson/Cousins
Improved B filter extending blocking >1100 nm and eliminating small light leaks that affected measurements of reddest stars in our initial filters
100% coated – no colored glass
Peak transmission guaranteed > 90%
<0.01%T(ave) typical out-of-band 300 – 1100 nm; additionally =<0.1% Tabs for B* * Striae-free, single fused silica substrates * 1/4-wave propagated wavefront prior to coating * <0.5 arcminute substrate parallelism * 3.000 +/-0.025 mm substrate thickness * Parfocal with all Astrodon filters * Edge-blackened * 1.25″ mounted ==== JOHNSON-COUSINS B* ====