I have some pieces of polarizing film from polarization.com, which are reasonably good and not too expensive, but I have some problems with them:
- They are too thick (only just fit in the filter slots), and probably related:
- There is significant loss of contrast and haze when a bright light is in the frame
- There is no anti-reflective coating
The thickness is, in part (I think), because they have an extra layer of quarter-wave-retardation to make them circular rather than linearly polarizing.
I'm particularly interested in using polarizing filters with my fisheye lens, for fun effects with sky and water, so thin, rear-slot solutions are the only option: glass filters would be ideal, but the glass from a normal polarizer is too thick for the rear slot, which is about .5-.8mm thick.
What other options are there? Also, what about ND gels in this format?