Astrodon 49.7 mm dia. Unmounted Gen2 I-Series Individual Red filter

Astrodon LRGB Gen2 I-Series Tru-Balance Individual Filters Only     Filter Sets Sold Here Astrodon LRGB Gen2 I-Series Tru-Balance Filters are designed to approximately equalize the flux of  Interline CCD detectors (formerly Kodak), including compensation for the solar photon flux.  The I-Series filters compensate for the lower red response of these Interline detectors affecting the design of the Green and Red filters.  The Luminance and Blue filters are the same as those in our E-Series.  This means that your RGB color combine weights will be approximately 1:1:1 within perhaps 10% for equal length exposures.  This can never be perfect, but it does allow you to take one exposure time for all of your RGB data and therefore, only just one corresponding dark exposure time.  Again, this saves you precious imaging time and thus, simplifies your imaging. Set includes Luminance (NIR/UV-blocked colorless), Red, Green and Blue filters 1.25″ mounted, 31, 49.7 mm dia.  3 +/-0.025 mm single 1/4 wave fused silica substrate before coating 30 arcsec parallelism  ~1:1:1 color combine weights for G2V white-point for Kodak Interline detectors Equal RGB exposures and one dark time Better color separation (see spectra) Better color rendition for galaxies based upon color theory Significant reflection and star halo reduction Spectral “gap” between green and red filters to reduce the effects of light pollution Highest efficiency blue filter with less UV Correct “teal” OIII color for planetary nebula (OIII signal >97% in blue and green) Parfocal with Astrodon‘s high-performance narrowband and near-IR Luminance filters Ultra-hard and durable sputtered coatings coated to the edge of each filter Proudly made in the U.S.A.