Lunt Blocking filter B1800, straight-through, 2" connection

Only Lunt Blocking Filters make the H-alpha observation possible and protect from dangerous radiation.

Lunt Solar Systems currently offers different blocking filter apertures for use with their H-alpha etalon systems. The blocking filters are absolutely required for the safety and performance of telescopes for solar observing! Blocking filters will be mounted at the eyepiece-side of the telescope, and protect against the dangerous radiation from the sun.

We are currently offering the B600d, B1200d, and B1800d in a 90° star diagonal, with 1.25" or 2" on the telescope side, and T2 (M42x0.75) and 1.25" on the eyepiece side.

The B600s, B1200s, and B1800s is also being offered in a straight through extension tube with T2 on both sides, 2" on the telescope side, and 1.25" on the eyepiece side. The T2-thread at telescope side will need a ring with a female T2-thread, as it is a male thread. The T2-thread has no mechanical stop!

The extension tube of the B3400s has a 2" connection on the telescope side, and a 2" receptacle and adapter for 1.25" eyepieces on the other side.

The Blocking Filter B600 is for maximum focal length 600 mm, B1200 is for 1200 mm, B1800 is for 1800 mm and the B3400 is for 3400 mm maximum focal length. This is the focal length of telescope for which that particular blocking filter will provide a full disk image of the Sun. A blocking filter larger than that required might be needed for imaging.

Lunt Solar Systems blocking filters contain a unique filter system. We can only warranty safety or performance if the blocking filter is paired with an original H-alpha front filter of Lunt Solar Systems.

Important hint: In humid air, blocking filters might tarnish, so keep yours dry. You can get little packages of silica gel for reducing humidity even more. Put one and the filter into a small freezer bag and seal it.

Safety informations: PDF Download