Lunt Solar Systems currently offers a total of four (4) blocking filter apertures for use with our Etalon systems, and they come in a selection of housing designs so that you can choose the best one for your visual or imaging applications. Significantly, the Blocking Filter houses additional filters which are required for the safety and performance of the solar package. In addition, Lunt Solar blocking filters contain a unique filter system. Another key point is we can only warranty safety or performance when one of our blocking filters is paired with a Lunt H-alpha filter or telescope.
To pick the proper blocking filter for you, take a look at the suggestions listed below for visual use and/or imaging use. Next, match what you want to do with the focal length of the telescope you will be using for solar work. Then, choose your choice of blocking filter from the drop-down options list above for all B600, B1200 & B1800 models. You can buy the B3400 Blocking Filter, housed in a 2" Straight Through Extension Tube, by clicking the link.
When imaging with a Lunt Solar System it is recommended that the user opt for the next larger blocking filter than that recommended for visual use. This is due to the fact that most imaging systems require additional "back focus". It's important to realize that the blocking filter be moved further up the light cone. As a result, the aperture of the blocking filter needs to be larger to allow for the larger cone size.
See the latest news and images of the Sun at NASA.