BAADER BESSEL R PHOTOMETRIC FILTER Size:65x65mm The William Optics Dr Flat

The William Optics Dr Flat Master is an apochromatic triplet 0

one ring with continuous M42 (T2) external thread

Another significant advantage of very low friction is that the risks of motor slipping during GOTO operation is virtually nil

The biggest piece has a weigth of only 15 kg – 33 lbs

BAADER BESSEL R PHOTOMETRIC FILTER Size:65x65mm The William Optics Dr FlatThe 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