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

This telescope comes with ESATTO 2" robotic microfocuser

The external layer is highly reflective (it is similar to Mylar) and blocks 99% of the sun's heat keeping your telescope cool

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