Astrodon Sloan Filter - r' 50mm Round - Unmounted
Astrodon Sloan Digital Sky Survey Filter - r' 50mm Round - Unmounted
The original Sloan Digital Sky Survey (SDSS) filters include five mostly non-overlapping filters covering 300 nm to the sensitivity limit of silicon CCD cameras near 1100 nm. They combined colored glass filters and short-pass dielectric coatings to steepen the low wavelength side of the bandpass. The [OI] (sky) emission line at 557.7 nm occurs between the g' and r' filters, and is reduced by using the SDSS filters.
The SDSS photometric system is the most common filter set used today. Typical research photometry up to magnitude 23 will be performed in this system, with professional (meter-class) telescopes. The Hubble Space Telescope is equipped with an SDSS set, and provides a large reference database for research.
The Astrodon Sloan filters achieve a steep cut-on and cut-off, and peak transmissions in excess of 95%.
The Astrodon Sloan Filters Also Feature:
- Sloan type u' g' r' i' z' band filters.
- Use only dielectric coatings to achieve steep cut-on, cut-off, & peak transmission exceeding 95%.
- Parfocal with all Astrodon LRGB and narrowband filters.
- Striae-free, single fused silica substrates.
- 1/4-wave propagated wavefront, prior to coating.
- Exhibit 0.5 arcminute substrate parallelism.
- 3.000 +/- 0.025 mm substrate thickness.
- Tested and recommended by AAVSO.
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Overseas Filter Purchase from OPT
great filter performs as expected for variable star observations