Blockfilter BF 5mm 1.25"

The blocking filter is the second element in any Coronado H-alpha system, it is just as crucial to your safety and the system's performance as the front element. Cannot be used without a Solarmax H-alpha front cell.

There are four versions of the Coronado Blocking Filter (BF):

• BF 5mm for telescopes up to 500mm focal length
• BF 10mm for telescopes up to 1000mm focal length
• BF 15mm for telescopes up to 1500mm focal length
• BF 30mm for telescopes up to 3000mm focal length