Baader Planetarium Fringe Killer Filter

Baader Planetarium Fringe Killer 31.7mm Filter

The Baader colour fringing blocker – Fringe-Killer – filter has been developed to

• block unfocused light in the red part of the spectrum (IR)
• suppress over 50% of the interfering stray light in the blue spectral range

all without drastically changing the colour impression of the resulting image. When using the filter fine details of lunar craters and planetary surfaces are much more apparent!

The Baader Fringe-Killer Filter prevents unwanted colour fringes in both the blue spectral range and in the IR above 700 nm! The visual impact initially corresponds to a minus violet (MV) filter, as opposed to this but the image colour remains broadly balanced. The filter is produced by applying modern DWDM plasma assisted coating technology, which allows the application of approximately 100 individual layers on a flat-optically polished face surface perfectly and consistently without compromising visual quality. Use of the filter also allows inexpensive China-refractors to reach a much improved imaging performance. The reduction of chromatic aberration corresponds to what is achieved by correction-based lens systems, which usually cost more than 20 times more.

Below clearly shows the visible colour correction of the Baader Fringe Killer.

Features

• Removes blue fringing as well as red fringing above 700nm.
• Forms in the range between 450 to 480 nm with a plateau at around 50% transmission rate, the coating becomes more complex to produce than even the narrowest Nebula filters.
• Achieved in the passband the highest transmission rate of all previously available colour fringe, whether filter or correction lens. From 486-656 nm all relevant deep sky wavelengths are completely transmitted. Visually this is enough light for even high magnifications.
• Built-in IR-cut filter for the range 656-1150 nm; perfect for the CCD and Digital Camera-use in deep sky, moon or planets.
• Provides the brightest image of all industrially produced colour error correction systems. Thus the Fringe Killer is a must for even the smallest telescopes.
• Removes blue fringing as well as red fringing above 700nm.
• Cancels the devastating intensity of the disturbing purple fringing in a new form, which was never implemented to date in astronomical filters
• Even weak nuances remain clearly visible in the planet due to the excellent colour balance.
• In conjunction with an RG-610 Red Filter produces a narrowband Ha-pass filter with an only 70 nm wide windows and 95% light transmission – at an incredibly low price!
• Plane-optically polished for perfect sharpness, even when the filter is assembled well before the focal point (or binocular digital camera insert).
• No deterioration of resolution with high magnification – as would happen with flame-polished (raw polished) glass, commonly used for all sorts of filters!
• Hight Quality Coating: Plasma-enhanced dielectric coatings result in hard, scratch-resistant and waterproof filters. Almost 50 layers on either side, carefully positioned as not to impair the optical quality of the substrate surface
• Makes the performance of a simple f/8 economy refractor look like a classic f/15 Fraunhofer achromat. See it to believe it!
• The combination of this filter with the Baader Neodymium Skyglow Filter (with Phantom-Group-Coating) results in balanced but improved contrast to the observations of fine lunar and planetary details.

Specifications

SKU (#)	2458370 (1.25″) / 2458375 (2″)
WEIGHT (KG)	0.059
TRANSMISSION RANGE	multiple bands (see spectral image)
FILTER THICKNESS (WITHOUT CELL)	2 mm
AR-COATING	Phantom Coating® Group, planeoptically polished
FILTER SIZE	1 25 inch / 2 inch
FILTER USAGE	Color Correction, IR-Cut
FILTER MOUNTED	Mounted (LPFC 6mm)
TYPE OF FILTER	Bandpass
SINGLE OR SET?	Single Filter
FILTER SHAPE	round