BAADER BESSEL I PHOTOMETRIC FILTER GEOPTIK15 2mm focuser drawtube

2mm focuser drawtube

Prima Luce Lab ESATTO 3" 65mm extension tube installed on Skywatcher Esprit 100ED

Length: 400 mm

Each USB port is equipped with ±15kV ESD surge protection for safe usage in very dry climates where static discharges can be an issue

BAADER BESSEL I PHOTOMETRIC FILTER GEOPTIK15 2mm focuser drawtubeThe Baader Bessel I filter is a precision grade photometric bandpass filter with a central wavelength window between 700 900nm. The UBVRI system was developed in the 1950s for the 0. 9m McDonald Observatory telescope and initially consisted of a Johnson UBV filter set, later extended by Cousins to include the R and I filters for the red region of the spectrum. The filters of the extended UBVRI system according to Johnson and Cousins include: U