Optolong UBVRcIc Photometric 5-Filter Set - 2"
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Optolong UBVRI Johnson-Cousins Photometric filters - Set of five mounted 2" filters for use in imaging filter wheels. Set includes Ultraviolet (U), Blue (B), Visual (V), Red (Rc), and Infrared (Ic) filters. J-C UBVRI filters are the standard for AAVSO photometirc data. Note that these are not Bessel photometric filters.
The Optolong UBVRI Filter Set is made with quality brand glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength (CWL).
UBVRI filters are not for astrophotography. In fact, they are used to do photometry. So it’s in a more scientific application. In photometry, you measure the light coming from a star. By calibrating the data with reference stars, we're able to get precise measurements on the flux coming out of a star. Combined with a measurement of the distance of the star (that is usually found by satellite to have precise measurements of far stars), we're able to find fundamental parameters of the stars. Those fundamental parameters are usually the mass, the radius and the temperature of the star.
WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
Technical Data
- Optical glass fine material
- Spectrum: 300-1000nm
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- Fine-optically polished to ensure accurate 1/4 wavefront and < 30 seconds parallelism over the both surfaces
- High transmission at major nebula emission lines (i.e. H-alpha 656nm, OIII 496nm&500nm, SII 672nm and H-beta 486nm)
- Precision off-band blocking, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm)
Useful Resources
Filter Cell Specifications
D = Filter Cell Diameter = 50.7 mm / 2.0 in
T = Total Filter Height = 7.1 mm / 0.28 in
C = Filter Cell Height (Excluding Male Thread) = 4.5 mm / 0.18 in
M = Male Thread Length = 2.6 mm / 0.1 in
F = USABLE Female Filter Thread Length = Not threaded, so you cannot stack additional filters
S = Glass Substrate Thickness = 1 mm / 0.04 in
CA = Clear Aperture = 45 mm / 1.77 in
Other Information
- Country of Manufacture: China
Optolong UBVRI Johnson-Cousins Photometric filters - Set of five mounted 2" filters for use in imaging filter wheels. Set includes Ultraviolet (U), Blue (B), Visual (V), Red (Rc), and Infrared (Ic) filters. J-C UBVRI filters are the standard for AAVSO photometirc data. Note that these are not Bessel photometric filters.
The Optolong UBVRI Filter Set is made with quality brand glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength (CWL).
UBVRI filters are not for astrophotography. In fact, they are used to do photometry. So it’s in a more scientific application. In photometry, you measure the light coming from a star. By calibrating the data with reference stars, we're able to get precise measurements on the flux coming out of a star. Combined with a measurement of the distance of the star (that is usually found by satellite to have precise measurements of far stars), we're able to find fundamental parameters of the stars. Those fundamental parameters are usually the mass, the radius and the temperature of the star.
WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
Technical Data
- Optical glass fine material
- Spectrum: 300-1000nm
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- Fine-optically polished to ensure accurate 1/4 wavefront and < 30 seconds parallelism over the both surfaces
- High transmission at major nebula emission lines (i.e. H-alpha 656nm, OIII 496nm&500nm, SII 672nm and H-beta 486nm)
- Precision off-band blocking, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm)
Optolong UBVRI Johnson-Cousins Photometric filters - Set of five mounted 2" filters for use in imaging filter wheels. Set includes Ultraviolet (U), Blue (B), Visual (V), Red (Rc), and Infrared (Ic) filters. J-C UBVRI filters are the standard for AAVSO photometirc data. Note that these are not Bessel photometric filters.
The Optolong UBVRI Filter Set is made with quality brand glass that has been multi-coated with an ion-assisted deposition technology to ensure scratch resistance and stability on the central wavelength (CWL).
UBVRI filters are not for astrophotography. In fact, they are used to do photometry. So it’s in a more scientific application. In photometry, you measure the light coming from a star. By calibrating the data with reference stars, we're able to get precise measurements on the flux coming out of a star. Combined with a measurement of the distance of the star (that is usually found by satellite to have precise measurements of far stars), we're able to find fundamental parameters of the stars. Those fundamental parameters are usually the mass, the radius and the temperature of the star.
WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.
Technical Data
- Optical glass fine material
- Spectrum: 300-1000nm
- Surface Quality: 60/40 (Refer to MIL-O-13830)
- Fine-optically polished to ensure accurate 1/4 wavefront and < 30 seconds parallelism over the both surfaces
- High transmission at major nebula emission lines (i.e. H-alpha 656nm, OIII 496nm&500nm, SII 672nm and H-beta 486nm)
- Precision off-band blocking, specifically the major emission lines of artificial light pollution (i.e. Na 589nm, Hg 435nm and 578nm)
Useful Resources
Filter Cell Specifications
D = Filter Cell Diameter = 50.7 mm / 2.0 in
T = Total Filter Height = 7.1 mm / 0.28 in
C = Filter Cell Height (Excluding Male Thread) = 4.5 mm / 0.18 in
M = Male Thread Length = 2.6 mm / 0.1 in
F = USABLE Female Filter Thread Length = Not threaded, so you cannot stack additional filters
S = Glass Substrate Thickness = 1 mm / 0.04 in
CA = Clear Aperture = 45 mm / 1.77 in
Other Information
- Country of Manufacture: China