Robert42 Works well for DSO but when I setup for Moon it will not allow shutter speeds fast enough to keep from blowing out 90% of the surface.
As a workaround, you might want to try neutral density (ND) filters.
https://en.wikipedia.org/wiki/Neutral-density_filter
The above page has a table of the ND designation vs how much they reduce transmission by. There are a couple of notations, shown in the various columns.
They are easy to find from places like Amazon if you are using camera lenses. But they are also available as 2" and 1.25" filters, from folks like Baader.
Also, if you are using camera lenses, I would recommend getting the fixed density filters instead of the variable density ones. You can first change the aperture of your lens/telescope (cardbord with hole in front of the OTA's aperture in case of an astrograph instead of a camera lens) to figure out how much you need to dim by.
Chen
