Telescope FiltersTeasing out the Details

Draw Tube Filter Eyepiece

Filters are for increased contrast and resolution of the moon and planets in visual or photographic applications.Color filters are an essential tool permitting the observation and photography of surface detail that is often virtually invisible without filtration. Solar filters are absolutely essential for safe viewing of the sun.

Planetary and lunar observation may sometimes be enhanced by the use of color filters to bring out subtle detail and increase contrast. Basic set includes the four most important 1.25" color filters: #15 Deep Yellow #25 Red #58 Green #80A Medium Blue

The Kodak Wratten Series

Kodak's Wratten series can be purchased in over a hundred colors and densities and can be mounted in slide mounts and simply held between the eyepiece and the eye.

#15 Deep Yellow 67% T

Moon - Enhances lunar features.Jupiter - Penetrates and darkens the atmospheric currents containing low-hue blue tones and enhances the orange and red features of belts and zones. Also useful for studies of the polar regions.Mars - Reduces the light from the blue and green areas which darkens the maria. oases and canal markings while lightening the orangish desert regions. Also sharpens the boundaries of yellow dust clouds.Neptune - lmproves detail in larger telescopes (11' and larger apertures).Saturn - Penetrates and darkens the atmospheric currents containing low-hue blue tones and enhances the orange and red features of bands and zones.Uranus - lmproves detail in larger telescopes (11" and larger apertures).Venus - Reveals low-contrast surface features.

#25 Red 14% T

Moon - Slightly improves lunar features.Jupiter - Useful for studying the bluer clouds.Mars - Ideal for observation of the polar ice caps and features on the Martian surface. Also sharpens the boundaries of yellow dust clouds.Mercury - lmproves observation at twilight when the planet is low near the horizon and in daylight it reduces the brightness of the blue sky to enhance surface features.Saturn - Useful for studying the bluer clouds.Venus - For daylight observing, it reduces the brightness of the blue sky. Occasionally deformations of the terminator are visible.

#58 Green 24% T

Moon - Enhances lunar features.Jupiter - lncreases the visibility of the Great Red Spot. Useful for observing the low-contrast hues of blue and red that exist in the Jovian atmosphere.Mars - Excellent for increased contrast of Martian polar caps, low clouds and yellowish dust storms.Saturn - Enhances white features in the Saturnian atmosphere.Venus - Useful for Venusian cloud pattern studies.

#80A Light Blue 30% T

Moon - Greatly enhances lunar details under dark sky conditions.Jupiter - Enhances the boundaries between the reddish belts and adjacent bright zones. Also useful on the Great Red Spot.Mars - Very useful during the violet clearing. Helpful in studying surface features and polar caps.Mercury-lmproves observation of dusky surface markings at twilight when the planet is low near the horizon.Saturn - Enhances low-contrast details between the belts and zones.Venus - Useful for increased contrast of dark shadings in upper Venusian clouds.Comets - Brings out the best definition in comet gas tails.Polarizing Reduces reflected polarized tight in the Earth's atmosphere.Moon/Planets - lnvaluable as it reduces irradiation and glare.Binary Stars - Helpful in splitting binary stars by reducing glare and diffraction effects around the brighter star of the binary pair.

Which One Do I Use for Jupiter?

► #15 Deep Yellow 67% T - Penetrates and darkens the atmospheric currents containing low-hue blue tones and enhances the orange and red features of belts and zones. Also useful for studies of the polar regions.

► #25 Red 14% T - Useful for studying the bluer clouds.

► #58 Green 24% T - lncreases the visibility of the Great Red Spot. Useful for observing the low-contrast hues of blue and red that exist in the Jovian atmosphere

► #80A Light Blue 20% T - Enhances the boundaries between the reddish belts and adjacent bright zones. Also useful on the Great Red Spot.

Filtering Mars

This is an amazing planetary filter wheel that gives you a large range of different colors in one unit! Includes a built-in 2X barlow lens and color indicator window . Great for planets, the moon or removing chromatic aberration from daytime telescope viewing. No more dropping eyepieces in the dark to change colored filters! Simply turn the knob on the front of the unit to try the various colors until you get a pleasing image. Moving the filter from one color to the next will bring out different details from the same object. Single filters can't do this.   There are no focus changes between colors

Spectrum Color Filter Wheel

Telescopic FiltersThe Basics in Review

Why Filter?►Slight to moderately light-polluted

skies►Heavily light-polluted skies►Diffuse and planetary nebulae►Horsehead, California and other faint

nebulae►Safe solar viewing

Filter Basics►Filters can certainly enhance one’s

lunar and planetary observing ►All leading manufacturers of

telescopes have a standard sequence of filters which are based on the Kodak "Wratten" series

►made to screw into the standard 0.965, 1.25 and 2 inch eyepiece

Filter Basics►screw into a threaded recess at the

end on the eyepiece furthest from the eye

►The eyepiece is then returned to the Draw tube

►They can also be stacked to give an almost endless array of effects.

►not recommend stacking more than two as this could produce loss of light, particularly in smaller instruments

How Do Filters Work?►any red features observed through the

filter are scattered and lost by the properties of the filter

►blue features will appear considerably stronger, being passed by the filter

REMEMBER: Filters filter things out!!!!!

4 Major Types of Telescope Filters

►Planetary or Color Filters►Moon Filters►Nebular and Light Pollution Filters►Solar Filters

Major Filter Vendors Celestron   

Coronado   Daystar   

Identi-ViewJMI   

Lumicon   Meade   Orion   

Thousand Oaks   

Lunar and Planetary Filters

Lunar FiltersGeneral Lunar filters are of a neutral

color and are used to control the Moon's brightness around Full Moon. Several of these can be stacked to achieve the desired effect, as loss of light is usually not a problem when dealing with the Moon.

Nebular and Light Pollution Filters

BAADER CONTRAST- BOOSTER A unique filter for many different astronomical tasks - incomparable in image sharpness compared to combinations of basic color filters,

The Baader Contrast–Booster is specially designed to improve the ubiquitous beginners telescopes - to provide a professional replacement for the simple ”dark green” Moon- & Solar-Filters made of ”raw polished” glass.   (Note: for solar observation use only in combination with Baader AstroSolar Safety Film!)

Properties: •  Eliminates the colour error inherent in popular economy Refractors •  Clearly puts the real quality of the lens on display•  Removes the bluish ”hue” (lack of contrast) during lunar, planetary, solar and terrestrial observation! •  Strongly emphasizes surface detail on Jupiter and Mars! If you have never seen the GRS (Great Red Spot) on Jupiter - with this filter you will! •  Over 95% transmission - provides a bright, brilliant image compared to the usual dark green color filters, used to bring out detail on Jupiter. Colour recognition will be retained! •  The ultimate in lunar filters! - Moon (and Sun!) appear much more natural in colour (with a slight yellowish tint), compared to the usual low priced dark green Moon-filters, usually offered for beginners telescopes. •  Completely removes distracting false colour and the resulting smeared and washed out image details. You have never ever seen the Moon (or the Sun with AstroSolar Safety Film) so tack sharp in an economy priced telescope! •  Blocks atmospheric ”stray light” (skyglow). Sky-background turns into pitch black! •  Fits each and every standard filter thread; •  Used with the (Optically polished) Baader Infrared Cut-Filter. In this combination all blue scatter as well as unfocused near infrared light is completely removed - an absolute MUST for digital imaging!

Meade Series 4000 Nebular Filters incorporate the very latest in interference coatings technology. Each filter includes more than 40 coating layers to reject unwanted light from urban light pollution, making nebulae and galaxies much easier to observe. The broadband filters are used for visual and photographic use. The Narrowband filters offer more exacting filtration for higher performance. The Narrowband filters are not designed for photographic use.

Orion Skyglow Broadband Light Pollution Filters

An Effective Weapon for Combatting Bright Skies, Bad Contrast The Orion SkyGlow is an advanced multilayer "interference" filter designed to enhance deep-sky observing in moderately light-polluted skies. It blocks the most common wavelengths of light pollution - predominantly produced by mercury vapor lamps - and allows higher transmission of critical hydrogen-alpha and hydrogen-beta lines.

Bright, light-polluted skies appear much darker in the field of view and contrast significantly enhanced, particularly emission nebulas like the Orion and Lagoon. Views of galaxies and clusters are also improved.

Available in 1.25" and 2"and as a thread-on for rear cells of Schmidt-Cassegrains.

Orion Ultrablock Narrowband Light

Pollution Filters

Dramatically Improves Views of Emission and Planetary Nebulas The UltraBlock is the filter for deep-sky observers located at highly light-polluted sites.

Blocks all forms of light pollution - mercury vapor and sodium emission bands - while passing the critical hydrogen-beta and ionized oxygen wavelengths.

With an UltraBlock, emission and planetary nebulas "surface" from the washed out background sky.

In dark skies, the UltraBlock also enhances the sky presence of a significant number of fainter deep-sky objects over unfiltered and wideband-filtered views.

Available in 1.25" and 2"and as a thread-on for rear cells of Schmidt-Cassegrains.

Lumicon Deep Sky Filters

The Lumicon Deep-Sky Filter is THE foremost broadband filter efficiently blocking ALL mercury-vapor and high & low pressure sodium-vapor lamp light, neon lights and airglow, while allowing the rest of the visible spectrum through. The superior contrast gain between the object you're viewing and the black background of space allows you to view galaxies, nebula, star clusters, comets, etc. wonderfully -- when observing from light-polluted urban skies -- making it the best all-around visual light pollution filter. The Lumicon Deep-Sky Filter's high transmission in the H-alpha end of the spectrum makes it THE ONLY premium astrophotographic filter on the market for not only color photographs, but also for black & white photos and CCD work. Lumicon tests every filter individually on a Perkin-Elmer Double-Beam spectrophotometer, inscribing on the filter its % transmission for each of the primary spectral lines .

Lumicon UHC Filter

The original Lumicon Ultra-High-Contrast narrow bandpass filter (24nm) isolates just the two doubly-ionized oxygen lines (496 and 501nm lines) and H-beta line (486nm) emitted by planetary and most emission nebulae, while blocking, completely the rest of the overall spectrum of light. The result is extreme contrast between the black background of space and the delicate photons of nebula light needed for near-photographic views of the Orion, Lagoon, Swan and planetary nebulae, among others. This makes the Lumicon UHC Filter the best all-around dark-sky filter on the market today. See for yourself -- it's truly amazing what the Lumicon UHC filter allows you to see! Lumicon tests every filter individually on a Perkin-Elmer Double Beam spectrophotometer, inscribing on the filter its % transmission for each of the primary lines. Do not settle for cheap, foreign-made imitations. Not intended for photographic use.

Oxygen III Filters

The renowned, original Lumicon OIII narrow bandpass filter (11nm) isolates just the two doubly-ionized oxygen lines (496 and 501nm lines) emitted by planetary and emission nebulae, while blocking the rest of the overall spectrum of light. The result is extreme contrast between the black background of space and the delicate photons of OIII light needed for near-photographic views of the Veil, Ring, Dumbbell and Orion nebulae, among other objects. See for yourself -- it's truly amazing what the OIII filter allows you to see! Lumicon tests every filter individually on a Perkin-Elmer Double-Beam spectrophotometer, inscribing on the filter its % transmission for each of the primary lines. Do not settle for cheap, foreign-made imitations. Do not settle for cheap, foreign made imitations. Not intended for photography (use the Lumicon Deep Sky Filter).

Lumicon Hydrogen-Beta Filter

The Lumicon H-Beta Filter isolates only the Hydrogen-beta line of the spectrum (486.5nm) while blocking, completely, the rest of the overall spectrum of light. The result is extreme contrast between the black background of space and the delicately attenuated H-beta light needed to view a few select, extremely faint objects such as the Horsehead, Cocoon and California Nebulae. In may cases the Lumicon H-Beta Filter is the ONLY way to view those objects. A steady, transparent sky, 8" or larger aperture (in most cases) and a maximum-efficiency exit pupil (7mm), combined with the Lumicon H-Beta Filter, all make an unbeatable combination for viewing those "notch in the belt" objects. Lumicon measures every filter individually on a Perkin-Elmer Double-Beam spectrophotometer, inscribing on the filter its % transmission for the primary H-beta Line. With this filter, all nebulae may be checked for H-beta emissions, with reference to views given by your other Lumicon filters. Not intended for photography.

Solar Eclipse Viewing Glasses

Wear Eclipse Viewing Glasses to protect your eyes from solar radiation any time you look directly at the sun or the sun's reflection. When looking at a solar eclipse, use proective eyeware whenever ANY PART of the sun, no matter how small is visible. $2.00.

Astro-Solar Filters

Full aperture and/or off axis filters for all the most commonly used telescopes in amateur astronomy. The cells are aluminum and all have three nylon thumb screws to facilitate a secure fit on the front of your telescope. The filter material itself is the famous BAADER AstroSolar Film. This film has set a new standard for white light filters and gives a very pleasing and high resolution image. The image color is a bluish white. The filters are available in photographic film also and this must be specified.