re: I don't have a sodium filter
About $50 to $70 depending on the size. I only know, because I've had my eye on one, but don't know if it will make a big enough difference to justify the cost.
telescope.com
Space/Science » in reply to re: I don't have a sodium filter
About $50 to $70 depending on the size. I only know, because I've had my eye on one, but don't know if it will make a big enough difference to justify the cost.
telescope.com