Gerald Sargent
29-03-2009, 06:56 PM
2" filters are supposed to fit a 48mm fine pitch metric thread.
They also should not exceed 5mms in shoulder height from the
threaded portion.
I have found that all my Baader filters have a thread diameter
of 48,7+mms which either means they will just grab a part turn
in a device or not fit at all. The height also means that they
cannot be used in most "colour wheel" type devices.
So be warned. Astronomic filters do comply with the standards.
Gerald.
They also should not exceed 5mms in shoulder height from the
threaded portion.
I have found that all my Baader filters have a thread diameter
of 48,7+mms which either means they will just grab a part turn
in a device or not fit at all. The height also means that they
cannot be used in most "colour wheel" type devices.
So be warned. Astronomic filters do comply with the standards.
Gerald.