BAADER BESSEL R PHOTOMETRIC FILTER Size:65x65mm one ring with continuous M42

one ring with continuous M42 (T2) external thread

Note: in order to connect the OAG-M-Pro to your image train

The William Optics Dr Flat Master is an apochromatic triplet 0

Optional storm protection kits are available separately

BAADER BESSEL R PHOTOMETRIC FILTER Size:65x65mm one ring with continuous M42The Baader Bessel R filter is a precision grade photometric bandpass filter with a central wavelength window between 550 800nm. 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