Baader UBVRI Photometrics filter set (5 filters)

Estimated shipping time 7-9 days

Baader UBVRI Photometric Filterset (4mm Glass)

Baader 4 mm thick UBVRI filters feature a proprietary design that strictly adheres to the classic Johnson/Bessel transmission specification. Unlike the classic construction that regularly has a thickness of 5mm or more, the Baader-filters are made of dielectric layers as well as absorption glasses. This allows for a smaller filter thickness of 4 mm. The original stack of pure colored glass had a thickness of 5 or 6 mm and would be too thick and too heavy for modern filter wheels.

In the old days, UBVIR-filters were used for photodetectors and no one would care if the huge stack of cemented absorption glasses would cause havoc in terms of inherent internal reflections. Our method of combining dielectric coatings with a combination of a short pass and long pass filters does provide for perfect off-band blocking into the far ends of the spectrum. This steep off-band-blocking would not be possible with pure dielectric layers over such a large transmission range.

• 5 filters:
  • • U
    • B
    • V
    • R
    • I
• Photometric Johnson/Bessel filter system
• partial dielectric design with BBAR minimized reflections
• Planeoptically polished, 4mm glass thickness
• non-ageing sealed coating edges

Transmission curve:

Specifications:

FILTER SIZE	1 25 inch	50 x 50 mm
MANUFACTURER	Baader Planetarium	Baader Planetarium
SKU (#)	2459440	2459444
EAN CODE	4047825101815
WEIGHT (KG)	0.145	0.145
TRANSMISSION RANGE	Transmission range after Bessel	multiple bands (see spectral image)
FILTER THICKNESS (WITHOUT CELL)	4 mm	4 mm
CWL (CENTRAL WAVELENGTH)	Bessel	Bessel
AR-COATING	dielectrically coated, planeoptically polished	dielectrically coated, planeoptically polished
FILTER USAGE	Specialty, UBVRI	Specialty, UBVRI
FILTER MOUNTED	Mounted (LPFC 6mm)	Unmounted
TYPE OF FILTER	Bandpass	Bandpass
SINGLE OR SET?	Filter-Set	Filter-Set
FILTER SHAPE	round	squared

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If you have any doubt, contact us at info@lunatico.es.