The BF-5 Blocking Filter from Coronado is the secondary interference filter in a Coronado H-Alpha solar viewing system. Blocking filters are not stand-alone devices; they must be used in conjunction with a SolarMax filter. In a solar viewing system, the blocking filter is just as crucial to the viewer's safety and the system's performance as the front element. This 5mm blocking filter, the BF-5, is compatible with telescopes that have a focal length that is equal to or less than 500mm.
Note! SolarMax filters are sold in kits that include a blocking filter. This blocking filter offered here is intended for viewers who have two different focal length telescopes that they intend to use with their SolarMax system.
- Must be used with a SolarMax filter
- 1.25" right angle diagonal, image size: 4.6 mm
- For telescopes with a focal length equal to or less than 500 mm