KRON/COUSINS UBVRI FILTERS Andover Corporation offers UBVRI filters as standard items. These filters are used to filter out and measure specific bands of light that are emitted by astronomical objects.    Two types are offered: the Johnson/Bessel and the Kron/Cousins. The Johnson/Bessell type is better suited for use with a photomultiplier tube whereas the Kron/Cousins type is better suited for use with a Silicon CCD. Both filter sets work very well but it is important to establish the type of measuring system you are going to utilize before purchasing any sets.   Both filter types utilize the same U, B & V filters. The R & I filters for each type are different; they are better matched to the response of the detector being used. Refocusing is always a problem when changing filters. Andover has minimized this problem by grinding and polishing all filters to very precisely controlled thicknesses.   The UBVRI filters are available in a range of standard and custom sizes. Contact Andover Technical Sales if you have any questions or require a quotation for a custom size or mounting.   BENEFITS  Options for professionals and amateurs alike Ideal for photometric calibration Isolate and measure large specific bands of light emitted by astrological objects

 

COATING CAPABILITIES  We work in the wavelength range from 193nm up to 14µm, including all of the Sloan DSS wavelengths. We manufacture filters with bandwidths ranging from extremely wide (multi-microns) to extremely narrow (sub-nanometer). Sizes range from 2mm to 305mm dia. Our Image Quality filters exhibit transmitted wavefront error as low as 1/20 wave, and parallelism down to 5 arc seconds or less. Andover routinely manufactures space-qualified filters using radiation-hard, non-outgassing materials. As with all of our filters, they exhibit superior stability and longevity. Our in-house engineers can help in designing a filter or coating to meet your specific requirements.    We offer a range of filters operating in the atmospheric transmission regions as well as narrowband filters suitable for detecting atomic emissions such as our H-Alpha operating at a wavelength of 656.281nm. This is typically used in solar observations and is the easier way for astronomers to trace the ionized hydrogen content of gas clouds.  Our narrow bandwidth H-Alpha filter will improve contrast aiding in the observation of solar flares.

 

A PARTIAL LIST OF OUR  DISTINGUISHED ASTRONOMY CUSTOMERS

 

Smithsonian Astrophysical Observatory - MA, USA US Naval Observatory - DC, USA USGS Cascades Volcan Observatory - WA, USA University of Florida - FL, USA Thunder Bay Observatory - Canada Vatican Observatory - Italy University of Hawaii - HI, USA Dutch Open Telescope - Spain HIPAS Observatory - AK, USA Big Bear Solar Observatory - PR, USA National Solar Observatory - CO, USA Arecibo Observatory - PR, USA National Observatory of Athens (NOA) - Greece Perth Observatory, Australia Lowell Observatory - AZ, USA Fairborn Observatory, AZ, USA

 

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