Astrodon Tru-Balance RGB filters have revolutionized CCD imaging. Their popularity is due to ease-of-use, high optical throughput and great resulting color for galaxies, star clusters and nebulae. There are two varieties of Tru-Balance filters - E-Series and I-Series.
E-Series filters are designed to approximately equalize the flux of Kodak's full-frame (E-Series) CCD detectors, including compensation for the solar photon flux. This means that your RGB color combine weights will be approximately 1:1:1 within perhaps 10%. This can never be perfect, but it does allow you to take equal time exposures for your RGB data and also just one corresponding dark exposure time.
- 1.25" mounted, 49.7 mm dia., 49.7 mm square
- ~1:1:1 color combine weights for G2V white-point for Kodak Full-Frame (E) detectors
- Best choice for backthinned and Sony detectors
- Equal RGB exposures and one dark time
- Better color separation (spectra)
- Better color rendition for galaxies based upon color theory
- Significant reflection and star halo reduction (see Alnitak image)
- Enhanced contrast for HII regions in galaxies
- Spectral "gap" to minimize effects of light pollution
- Highest efficiency blue filter with less UV
- Correct "teal" OIII color for planetary nebula
- More parfocal - thickness 3+/-0.025 mm*
- Parfocal with Astrodon's high-performance narrowband and near-IR filters
- Striae-free 1/4 wave fused silica substrates
- 30 arcsec parallelism
- Ultra-hard and durable sputtered coatings
