Optolong LRGB CCD Filter Set – 31mm Unmounted – LRGB-31U Optolong

Optolong LRGB Filter Set – 31mm Unmounted

This versatile LRGB Filter Set by Optolong give you an array of four 31mm unmounted filters. The included filters are Red, Green, Blue, and Luminance. Designed for de-bayered monochrome CCD and CMOS cameras, these filters are excellent for both planetary and deep-sky imaging. Like all Optolong filters that are designated “CCD”, this filter set blocks infrared wavelengths from 700nm to 1100nm so there is no need to use a separate IR-Cut filter.

The transmission of each filter is designed for maximum contrast and beautiful results. There is a gap between the green and red filters that improves color balance and separation by blocking out the Sodium line at 589nm. Also, OIII emission is allowed to overlap on the blue and green filters for more natural color.

The Optolong 31mm Unmounted LRGB Filter Set is made with Schott glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength or CWL. This filter set is designed to be used in color filter wheels that accept 31mm unmounted filters in a round format.

 

Quality Filter Materials:

• Schott B260 substrate material from Germany, 3.0mm thick

• Multiple layers of anti-reflection non-cementing coatings applied via electron-beam gun evaporation with Ion-assisted deposition

 

Optolong Filter Manufacturing Processes and Parameters

• Filter substrate is fine-optically polished to 1/4 wave and <30 parallelism over both surfaces

• Surface quality, according to MIL-O-13830, is 60/40

• 95% transmission at bandpass

• Infrared wavelength 700-1100nm cut-off

• Optolong’s planetary rotation system is a homogenous and precise coating procedure that ensures both high transmission of pass-band and optical density of off-band

• Each filter comes with a plastic case with high-pressure EVA case lining

 

About Optolong

Optolong is the Astronomy Filters division of Yulong Optics, an optical filter design, and processing company out of Kunming, China that has provided filters for over 700 optical companies since 1999. All Optolong filters pass European Union RoHS requirements and have been certified by TUV Rheinland and Bureau Veritas.