Baader Contrast Booster Filter
Planeoptically Polished and Phantom Group Coated
Discover your telescope anew – with the Baader Contrast Booster:
A unique filter for many different astronomical tasks; incomparable in acuity to combinations of generic colour filters, made of raw polished glass – where surface inaccuracy adds up in the optical wave front to an unbearable degree. Especially designed to improve the beginners telescopes – to provide a professional replacement for the simple “dark green” Moon & Solar-Filters made of “raw polished” glass.
For Solar Observation use only in combination with Baader AstroSolar Safety Film!
Much more than a simple minus-violet filter. Based on the popular Baader Moon&Skyglow filter, the Baader Contrast-Booster takes contrast enhancement and skyglow reduction to the maximum level possible from a filter. Not only does this filter deliver a significant enhancement of planetary and lunar contrasts, but it is designed to also totally eliminate the damaging blue defocused haze present in achromatic refractors. Gone are the annoying blue halo and obscuring haze that surround and smear resolution and contrast. Subtle contrasts and colors are boosted, while displaying the full resolution your scope is capable of.
The Contrast-Booster combines a special proprietary melt of Neodymium glass with a carefully designed 23 layer dielectric long-pass blocker on one face, and a 7-layer ultra-low antireflection coating on the other face. By aggressively filtering out the defocused blue wavelengths, a light yellow tint is imparted to objects (noticeably less than a typical yellow filter). The special coatings enable over 95% transmission across key portions of the visible spectrum (including H-Alpha). This results in a filter that retains the colors and color contrasts in tough subjects like Jupiter, without excessive image dimming. Cloud bands retain their ruddy red hues, but now become more striking in contrast. The Great Red Spot finally becomes easier. Planets and Lunarscapes are set against a jet black sky. The Contrast-Booster is a must for Solar observing (with Baader Astro Solar).
As many users have found, this is a great filter for Mars! The views of Mars with all telescopes (including reflectors and apochromats) benefit from the RGB filtration plus blue blocking.
Combined with the Baader UV-IR-Cut Filter, the Contrast-Booster makes the ideal filter set for digital imaging. Rather than add the cost of additional IR filtration (only needed for digital imaging), the Baader Contrast Booster has been optimized for visual use. Digital imagers can simply add our Baader UV-IR-Cut Filter when needed. The true 1/4 wave fineoptically polished surfaces guarantee the sharpness and contrast of the image. Filters are available in both 1¼” and 2″ sizes.
The base substrate is a special custom melt of Neodymium doped glass, designed for specific transmission characteristics, and made only for Baader Planetarium. In addition to it’s unique spectral characteristics, the Contrast-Booster offers Baader’s hallmark optical and mechanical features that set it apart and result in the best possible image sharpness, contrast, and real-world durability
- Eliminates the colour error of 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 colour 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 color (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 into 1¼” and 2″ standard filter threads.
- Planeoptically polished, suitable for being used in front of a binocular viewer, or for a-focal image projection during digital imaging (way in front of the focal plane).
- No deterioration of resolution with magnifications of 200x and more – as with “raw polished” (flame polished) glass.
- Substrate (glass melt) Neodymium doped glass.
- Coating / rear face: 7-layer hard-multicoating, featuring 0.25% reflection.
- Coating / front face: 23-layer dielectric long pass blocker.
- Ionbeam hardened coatings on both faces, absolutely scratch resistant – may be cleaned any time without fear with Baader Optical Wonder Fluid.
- A significant part of city light air pollution, as well as atmospheric Airglow is removed from the telescopic image.
The Transmission Line of Baader Contrast Booster
The transmission curve shows the light transmittance in percent versus the light wavelength in nanometres. Note the high transmission for visual observations of H-alpha (98%), H-beta (87%) and OIII (82%).
In a light polluted town or city mercury and sodium vapour street lights emit at 435nm and between 570-590nm. Here the filter transmission is between 0.3 and 3%.
Together with the Baader UV / IR cut filter Baader Contrast Booster is additionally an optimal filter for CCD images from light-polluted big city and metropolitan area (see second filter curve).