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Baader S II 8nm CCD Narrowband-Filter

$149.00
SKU FSIIN-1 (Baader #2458430)
Filter size

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Description
  • 3 mm glass thickness
  • non-ageing sealed coating edges

CCD imagers will find Baader's Premium Narrowband CCD passfilters to deliver the absolute highest contrast deep sky images in H-Alpha, H-Beta, Oxygen III, and Sulfur-II, with the shortest exposures possible. Their ultra-narrow bandwidths have extremely high transmissions, while completely rejecting light pollution as well as the important blocking of longer wavelengths.

The high optical quality of the Baader narrowband filters guarantees no loss in sharpness or contrast. Each substrate is fine-optically polished plane parallel to deliver a smooth and accurate 1/4 wavefront over the entire surface. This special custom polishing operation sets Baader filters apart from the standard commercially precision polished filter substrates used by most other filter manufacturers. 

In addition to their transmission properties, the Baader coatings were developed with another key goal in mind - eliminate the annoying reflections present in other narrowband astro-filters. To achieve this freedom from reflections, along with excellent out of band blocking, required careful design and testing of the coating stacks.

Coatings are professionally applied in Germany by the most sophisticated equipment available today, ensuring high consistency for bandpass centering, transmission, and out of band blocking. The anti-reflection coatings are designed to prevent halos and balanced to prevent physical deformation of the optically flat substrates. The ultra-hard ionbeam deposition ensures the coatings will never degrade from use or normal cleaning. Each filter is coated individually, permanently sealing the coating edges, in order to guarantee lifetime coating durability and uniformity. Baader mil-spec coatings won't degrade, peel or flake off, unlike the coatings of filters that have been simply cut out of pre-coated sheets of glass. This cutting operation leaves the coating edges rough and torn which enables penetration of moisture between the coatings and substrate.

These filters are available in three sizes, standard 1¼", 2", and a 50.4mm diameter bare substrate (unmounted) for use in SBIG STL and similar cameras. A new unmounted 50mm square version of the H-a filter is now available for large format cameras (H-b, O-III, and S-II 50mm Square filters are due in late summer of 2009). Clear parfocal filters are also available to assist in focusing.

Why Baader Planetarium Filters?

Transmission Curve
The transmission plots are not theoretical curves - but an actual measurement taken of Baader S-II filters.

S-II Transmission Curve
S-II Transmission Curve



Specifications

1.25"

MANUFACTURER Baader Planetarium
SKU (#) 2458430
EAN CODE 4047825009272
WEIGHT (KG) 0.059
COLOUR Black
TRANSMISSION RANGE S-II
FILTER THICKNESS (WITHOUT CELL) 2 mm
HBW (HALFBANDWIDTH) 8nm
CWL (CENTRAL WAVELENGTH) 673 nm
AR-COATING dielectrically coated, planeoptically polished
FILTER SIZE 1 25 inch
FILTER USAGE CCD, IR-Cut, S-II
FILTER MOUNTED Mounted (LPFC 6mm)
TYPE OF FILTER Narrowband
SINGLE OR SET? Single Filter
FILTER SHAPE round

2"

MANUFACTURER Baader Planetarium
SKU (#) 2458431
EAN CODE 4047825009265
WEIGHT (KG) 0.065
COLOUR Black
TRANSMISSION RANGE S-II
FILTER THICKNESS (WITHOUT CELL) 2 mm
HBW (HALFBANDWIDTH) 8nm
CWL (CENTRAL WAVELENGTH) 673 nm
AR-COATING dielectrically coated, planeoptically polished
FILTER SIZE 2 inch
FILTER USAGE CCD, IR-Cut, S-II
FILTER MOUNTED Mounted (LPFC 6mm)
TYPE OF FILTER Narrowband
SINGLE OR SET? Single Filter
FILTER SHAPE round

36mm

MANUFACTURER Baader Planetarium
SKU (#) 2459432
EAN CODE 4047825023780
WEIGHT (KG) 0.026
COLOUR Black
TRANSMISSION RANGE S-II
FILTER THICKNESS (WITHOUT CELL) 2 mm
HBW (HALFBANDWIDTH) 8nm
CWL (CENTRAL WAVELENGTH) 673 nm
AR-COATING dielectrically coated, planeoptically polished
FILTER SIZE 36 mm
FILTER USAGE CCD, S-II
FILTER MOUNTED Unmounted
TYPE OF FILTER Narrowband
SINGLE OR SET? Single Filter
FILTER SHAPE round

50.4mm

MANUFACTURER Baader Planetarium
SKU (#) 2458432
EAN CODE 4047825009258
WEIGHT (KG) 0.07
COLOUR Black
TRANSMISSION RANGE S-II
FILTER THICKNESS (WITHOUT CELL) 3 mm
HBW (HALFBANDWIDTH) 8nm
CWL (CENTRAL WAVELENGTH) 673 nm
AR-COATING dielectrically coated, planeoptically polished
FILTER SIZE 50.4 mm
FILTER USAGE CCD, IR-Cut, S-II
FILTER MOUNTED Unmounted
TYPE OF FILTER Narrowband
SINGLE OR SET? Single Filter
FILTER SHAPE round

50x50mm

MANUFACTURER Baader Planetarium
SKU (#) 2458433
EAN CODE 4047825022745
WEIGHT (KG) 0.073
COLOUR Black
TRANSMISSION RANGE S-II
FILTER THICKNESS (WITHOUT CELL) 3 mm
HBW (HALFBANDWIDTH) 8nm
CWL (CENTRAL WAVELENGTH) 673 nm
AR-COATING dielectrically coated, planeoptically polished
FILTER SIZE 50 x 50 mm
FILTER USAGE CCD, IR-Cut, S-II
FILTER MOUNTED Unmounted
TYPE OF FILTER Narrowband
SINGLE OR SET? Single Filter
FILTER SHAPE square

65x65mm

MANUFACTURER Baader Planetarium
SKU (#) 2459412
EAN CODE 4047825023704
WEIGHT (KG) 0.087
COLOUR Black
TRANSMISSION RANGE S-II
FILTER THICKNESS (WITHOUT CELL) 3 mm
HBW (HALFBANDWIDTH) 8nm
CWL (CENTRAL WAVELENGTH) 673 nm
AR-COATING dielectrically coated, planeoptically polished
FILTER SIZE 65 x 65 mm
FILTER USAGE CCD, S-II
FILTER MOUNTED Unmounted
TYPE OF FILTER Narrowband
SINGLE OR SET? Single Filter
FILTER SHAPE square

 

Downloads

FAQ - Problems with filters can have the strangest causes

Halos - No Problem!