SPQI Equipment Visible Filter
A cross-section of the visible-light filter assembly:
A close-up of the lens in-mount:
A close-up of the longpass filter in-mount:
An example of a completed visible-light filter unit (properly connected):
A cross-section of the visible-light filter assembly:
A close-up of the lens in-mount:
A close-up of the longpass filter in-mount:
An example of a completed visible-light filter unit (properly connected):