I bought a GSO polarizing filter some time ago, and it works fine both during the day and at night, but I was thinking that maybe a ND filter with 25% light transmission would be a good addition because the sharpness with a polarizing filter is not ideal, particularly for astrophotography, while I have read it is much better with a ND filter.
What do you think? And do you know what the light transmission of the GSO polarizing filter is?
Maybe I should have bought two polarizing filters to adjust the amount of light, but I guess the sharpness would still have suffered?
