Baader Contrast Booster 1.25"

Contrast Booster 1.25" - Contrast enhancement and reduction of false colour for refractors

The Contrast Booster is a further development of the simplier minus violet filters. It cuts off the blue part of the spectrum with its shorter wavelengths nearly complete - the false colour of achromatic refractors is nearly fully removed.

For which systems is the Contrast Booster recommended?

For every achromatic refractor from 130 mm aperture and bigger - if the intention is removing its false colour. The telescope´s image gets a yellowish colour fog similar to minus violet filters but with significantly better results in contrast and sharpness.

Filter curve

It is easy to see that the short-wavelength part below 450 nm is completely blocked. Similar to the Skyglow Neodyminum, contrast enhancement is achieved by selective blanking out parts of the spectrum. Especially for lunar and planetary observation the contrast is increased like with a combination of colour filters.

Characteristics and fields of use

• Eliminates false colour of achromatic refractors. It is recommended for 5" and bigger. For smaller telescopes, we recommend the Fringe Killer.
• Removes the blue halo at lunar, solar and planetary observation and the loss of contrast.
• Removes the blue halo at digital photography and blocks IR which would blur the image. A color cast from the filter is largely eliminated by white balancing.
• Surface details on Jupiter and Mars become more intense. If you never saw the Great Red Spot on Jupiter before - now you will have success!
• More than 95% transmission! In opposite to dark green filters formerly used for Jupiter, a colourful, bright and brillant image is achieved.
• Ultimative moon filter - the moon and the sun appear more naturally as with classical green moon filters (often delivered with cheap beginner telescopes). Disturbing glare is removed. You never saw the moon and the sun (with appropriate solar filter!) that sharp in a beginner telescope!
• Blocks disturbing atmospherical straylight (Skyglow). The skies background becomes black.
• Fits into all standard filter threads and can be combined with other filters. Cell height: 6 mm without external thread, 8 mm with M48 external thread
•  Plano-optically polished; can be used as a single filter for bino viewing or for afocal projection with digital cameras (far from the focal plane).
• No loss of sharpness at magnifications above 150x compared with raw polished (flame treated) glasses.
• Substrate: Neodymium doted colour glass, 2 mm thick
• Coating/back side: 7-layer multi-hardcoating
• Coating/front side: 23-layer Ion-beam long pass block coating
• Hard and scratch proof coating on both sides - can be cleaned often.