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Home > Optical Filters > Astronomical Filter
Astronomical Filter
Asahi Spectra has supplied astronomical filters to world famous observatories,
institutes or universities over 10 years.
Unlike cheap astronomical filters for the amateurs, Asahi astronomical filters are
definetely manufactured for professional astronomers to meet rigid specifications
and environmental durability.
New discovery and progress of science shall be emerged by Asahi filters.
Asahi astronomical filters are actually installed on telescopes in Hawaii, Chile,
Canary, Arizona, South Africa, Australia or other important observatories.
| Asahi filters has been supplied a installed to... |
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Advantage of Asahi Astronomical Filters |
- Optimized interference film design in consideration of convergent beam.(e.g. F/1.5)
- This shall be the great advantage for narrow bandpass in NIR wavelength.
- Approximate 300 x 300mm with coating uniformity over the clear aperture
- Image quality
- High transmission in particular UV wavelength
- Actual transmission data by text file available
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We always wish to cooperate with professional astronomers and contribute to the progress of science.
Contact us if you are interest in our custom-made filters.
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| 1. SDSS Filters (u',g',r', i',z'-band) |
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SDSS(Sloan Digital Sky Survey) photometric systems are now the most common, important and unignorable in astronomy.
We proudly supplied SDSS filters for Apache Point Observatory, where they are used as the original SDSS photometric systems.
We know the specifications SDSS project specified, and strictly observe them.We promise that we will supply genuine SDSS filters which completely meet the original specifications for you. |
| 2. Johnson / Bessel Filters (U,B,V,R,I) |
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Though more basic and rather classical photometric system, Johnson / Bessel filters are still important for astronomers.
Each transmission curves are the data which we manufactured according as typical Johnson / Bessel recipes.
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| 3. Narrow Bandpass Filters |
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| Stroemgren u filter |
H-alpha filter |
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Some filters will be installed in the convergent beam. As you know, spectral performance depends on angle by incidence.
Especially in narrow bandpass, the influence of convergent beam must be considered to keep ideal center wavelength or high
transmittance. We have developed the best method to design, by which you will be able to obtain the best performance of filters.
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| 4. Pan-STARRS Filter (g, r, i, z, y) |
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Pan-STARRS -- the Panoramic Survey Telescope & Rapid Response System --
is an innovative design for a wide-field imaging facility being developed
at the University of Hawaii's Institute for Astronomy. The University of Hawaii
has set up an international consortium in the Pan-STAARS Telescope No.1 comprised
of astronomers from Germany, the USA, the United Kingdom and Taiwan to operate and
analyze the data from the telescope. Pan-STARRS photometric filters must be getting
important in the future.
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| 5. Astronomical Near-Infrared Filter (Z, Y, J, H, K) |
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Asahi is currently challenging to develop some important NIR filters for astronomers such as WFCAM/VISTA.
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| 6. Large Filter for Large Wide-Field Telescope |
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We are launching to develop large filter, which will be quite important for wide-field
observatories (HSC, LSST, DEC, Pan-STARRS or WIYN) in the future.
We can produce filters as large as 300x300mm at this moment. By using our propriety technique,
the variation of center wavelength, cut-on or cut-off wavelength can be minimized.
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 Measuring Point |
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Filter Size : 300 x 300mm
Variation at 350nm : Approximate 1nm*
*It depends on the target wavelength
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