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FREE Customer Support
Casanova's Sport Optics Department
Tip #108
Use a Petzl Micro Headlamp upon your
head when partaking in your nocturnal astronomical hobby and/or work. |
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Meade? Series 4000?
Color Filters
Instructional Guide Color Filter
Primer - Using Meade Series 4000 Color Filters on the Moon and Planets |
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Meade Color Filters are manufactured of the highest-quality
optical glass, dyed-in-the-mass, and coated on both sides of the filter glass to increase light
transmission. The clear aperture of each filter is 26mm. Meade Color Filters are mounted in machined
cells which thread into the barrels of virtually every eyepiece with 1.25" outside barrel diameter (O.D.)
available today, including all Meade 1.25" O.D. eyepieces. Each filter features a second thread
inside the filter cells to permit filter stacking, to achieve selective filtration of the visual
color spectrum.
The most important
purpose of color filters in astronomical applications is in the enhancement of visual detail,
and increase in observable contrast, on the Moon and planets. In this application, filters
often provide the difference between seeing fine detail or not. This page is a
primer on the use of color filters in lunar and planetary observing.
Casanova's Color Filters In
Astronomical Applications Chart |
Wratten
Number
Common
Name
Light
Transmission
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#8 Light Yellow
83%
Light Transmission |
- Useful in observing red and
orange-colored phenomena in the belts of Jupiter, and in enhancing the
level of observable detail of small orange-red zonal features within the
belts of the planet.
- Increases contrast of maria on Mars.
- Results in improved resolution of detail
on Uranus and Neptune in instruments of 10" aperture and larger.
- A popular filter for the enhancement of
lunar features, particularly in telescopes of 8" aperture and smaller.
Casanova's Sport Optics
Department |
#11 Yellow-Green
78%
Light Transmission |
- Contrasts well with red and blue
characteristics of surface features on Jupiter and Saturn.
- Darkens the maria visible on Mars and
improves visible detail on Uranus and Neptune in larger telescopes.
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#12 Yellow
74%
Light Transmission |
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Contrasts strongly with
blue-colored features on
Jupiter and Saturn, while
enhancing red and orange
features. Lightens red-orange
features of Mars, while
reducing or blocking the
transmission, and thereby
increasing the contrast, of
blue-green areas. Useful in
increasing the contrast of
lunar features in telescopes
6" aperture and larger.
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#21 Orange
46%
Light Transmission |
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Reduces or blocks transmission
of blue-green wavelengths. Use
on Jupiter and Saturn to
enhance detail in the belts
and polar regions. Sharpens
boundaries between
yellow-orange areas and
blue-green regions on Mars,
resulting in a darkening of
edge-detail in the maria.
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#80A Blue
30% Light Transmission |
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Most popular filter for the
study of Jupiter and Saturn.
Enhances contrast of rills and
festoons in Jupiter's cloud
belts, as well as details of
the Red Spot. Brings out
detail in Saturn's belts and
polar phenomena.
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Very useful as a
contrast-enhancing lunar
filter.
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#82A Light Blue
73% Light Transmission |
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Useful on the Moon, Mars,
Jupiter, and Saturn, this
subtle pale blue filter
enhances areas of low contrast
while avoiding significant
reduction of overall image
brightness.
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ND96
(Neutral Density) 0.9 Density
13% Light Transmission |
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This neutral density filter
transmits uniformly across the
entire visual spectrum. As
such, it serves as an
excellent filter to reduce
glare and irradiation when
observing the moon with any
telescope 4" and larger.
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The ND96 filter may also be
employed in the splitting of
close double stars, where one
of the binary pair
significantly exceeds the
other in brightness.
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