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Astronomy Filters

All Astronomy Filters made by Silicon Valley Optics Technology Inc. (SVOTek) are guaranteed with 100% customer satisfaction. If the customer is not satisfied with a filters performance, it can be sent back for a full refund. SVOTek provides life warranties for all our Astronomy filters.
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SVOTek Astronomy Filter Descriptions

OIII Filter

The SVOTek OIII filter is a very specifically designed narrow band-pass filter for the visual observation of gaseous and planetary nebulae. This extremely narrow pass-band separates the two OIII lines which results in a substantial contrast gain to the object being observed. This filter is used to view very faint super nova remnants and faint planetary nebulae. This filter is also used as a light pollution filter to eliminate unwanted wavelenghts of ambient sky light.

Comet Filter

The SVOTek Comet Filter is a narrow band-pass filter that improves the contrast of the ionized oxygen tail of gaseous comets. It also improves the contrast of the coma (or head) of the comet against the dark night sky. This filter passes green light of 50nm which is emittd by ionized oxygen. In addition, it passes wavelenghts of 511nm to 514nm emitted by carbon molecules. This filter allows one to determine if a comet is gaseous or dusty in composition.

Deep Sky Filter

The SVOTek Deep Sky Filter is a very popular nebula filter used to block ambient light and enhance the contrast of nebula in the dark night sky. This filter blocks the light pollution that is generated by high and low pressure mercury and sodium vapor lamps, neon lights and sky glow. This filter passes the visible spectrum and infrared light which makes it an ideal choice for photography of deep sky objects in light polluted skies.

H-Beta Filter

The SVOTek H-Beta Filter is a narrow-band nebula filter that allows visual observation of very faint gaseous nebula. This filter isolates the hydrogen-beta wavelength of 486nm to a narrow-band of on 9nm. This filter provides maximum contrast when observing faint gaseous nebula such as the Horsehead, Cocoon and California Nebula. In addition, this filter blocks the unwanted light prduced by light polluted skies.

UHC Filter

The SVOTek UHC filter is an Ultra High Contrast Filter provides ultimate contrast when viewing deep sky stars and nebula. This filter passes the wavelengths of the OIII oxygen lines (496nm & 501nm) and the H-Beta line of (486nm) while blocking all other wavelengths. It effectively filters out light pollution from scattered light and sky glow. The strong filtering of light pollution allows excellent viewing of both gaseous and planetary nebula by providing good contrast between the object and dark night sky.