BAADER BESSEL B PHOTOMETRIC FILTER Size:36mm 30B303A: for small flat fields

30B303A: for small flat fields with a diameter of 165mm

8kg fully assembled

You can even use UV-filters (such as the Baader U-Venus-filter) or IR-pass-filters and achieve surprisingly good contrast

A great alternative use of your camera lenses for wide field astrophotography

BAADER BESSEL B PHOTOMETRIC FILTER Size:36mm 30B303A: for small flat fieldsThe Baader Bessel B filter is a precision grade photometric bandpass filter with a central wavelength window between 400 500nm. 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