Optolong L-eXtreme Dual 7nm Ha/OIII Narrowband Filter - 2" Diagonals The finely made glass lens

The finely made glass lens acts as a beamsplitter to combine the natural sky background with the superimposed red pointing "star

It attaches directly to the SCT threads on the rear cell of the telescope or similar telescope

This Celestron 12-36x 60 mm LandScout Spotting Scope with Smartphone Adapter features a rugged

QuikFinder attaches without drilling and is easily removed from its baseplate for storage

and it has a 45 mm wide Vixen type dovetail plate for mounting

Optolong L-eXtreme Dual 7nm Ha/OIII Narrowband Filter - 2" Diagonals The finely made glass lensThe L eXtreme filter from Optolong is 7nm dual band in that passes Ha and OIII emission lines. The advantage of the L eXtreme filter over the L eNhance, which is a tri band filter, is that there are no transmission between the H beta and OIII lines, as there is no nebula emission lines there. In this case, it isn't letting light pollution come through so that maximizes a nebula's signal and makes the sky background darker while imaging. The L eXtreme