mostly non-overlapping filters covering 300nm to the sensitivity limit of silicon CCD cameras near 1100nm. 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 557.7nm 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%.