20071007 Sun

Seeing was 3-4/10, transparency like 1-2/10, AR972 still there. Low transparency is washing out contrast, only 1/4 of the whole histogram contains signal. The close up is taken by 3x.

1401 (GMT+8), prominence only:-


1405 (GMT+8), monochrome and color versions:-



1413 (GMT+8), close up of AR972:-


Experiment was also conducted with 52mm red filter as ERF with PST etalon and it works, unlike the Ranger. The Borg 45ED II is f/7.2 while the Ranger is f/6.86, that's about the critical focal ratio for the PST etalon to work.