Canon 93517 - Manual (Page 17)

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" Polarizing Filter Set: – #93608
Ambient daylight is normally comprised of multiple
wavelengths of light, vibrating in multiple planes. The
Eyepiece Polarizing Filter Set transmits only light moving
along a specific plane, thereby increasing the contrast
between surfaces with different planar transmissions.
Generally, the polarization effect makes blue skies a
deeper blue, eliminates surface reflections and helps
reduce atmospheric haze.
The Polarizing Filter Set is intended for visual use. It’s particularly useful for reducing
glare while observing the moon, double stars, the planets and terrestrial subjects – all
without affecting the color of the object being observed.
The Filter Set is comprised of two filters that thread into either the eyepiece or the
filter adapter, which comes with the set. When one filter is used alone, you get 30%
light transmission. When both filters are used together, you can vary the degree of
transmission. By causing the amount of transmitted light to vary, the filters become,
in effect, a continuously variable neutral density filter. At
maximum density, the Polarizing Filter Set transmits only 5%
of entering light.
Skylight Filter/Dust Seal – #93621
If you were to use only one filter, Celestron’s Skylight
Filter/Dust Seal would be your most versatile choice. This
general purpose, Wratten #1A filter improves color saturation
and balance, increases visual and photographic contrast, helps
to decrease glare in lunar and planetary observing, and penetrates atmospheric haze.
It’s also an inexpensive way to protect your investment in quality optics. This filter
threads onto the rear cell of your Celestron C5, C8, C9
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, C11 or C14 telescope to
serve as an effective dust seal. By leaving the Skylight Filter/Dust Seal on when
removing or attaching other visual accessories, you prevent dust and other atmospher-
ic contaminants from entering the rear of your telescope. Needless to say, it’s much
easier to clean a dusty filter than a dusty primary mirror, secondary mirror and
corrector plate.
The Skylight Filter/Dust Seal must be threaded onto the rear cell of the instrument
before any other accessory is installed. The female end attaches to the rear cell of the
C5, C8 and C9
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telescopes and the reducer plate of the C11 and C14 telescopes. All
additional accessories mount onto the exterior/male threads.
Moon Filters
Celestron’s Moon Filters are economical eyepiece filters for
reducing the brightness of the moon and improving
contrast, so greater detail can be observed on the lunar
surface. The clear aperture is 21mm for the 1
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" filter and
10mm for the .96" filter. Transmission is about 18%.
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" Moon Filter [94119-A]
.96" Moon Filter (for Economy and SMA Series
eyepieces) [94119-B]