I've only used ND filters in the past, but it occurred to me today that perhaps I've been missing a trick and ought to be using low contrast filters in cases of strong backlight. Anyone had much success with these?

In terms of other filters that might come in handy, well, I suppose most of it could be done in post if one bothered. But I'm kind of interested in mist and fog filters that might give a halo effect to highlights, and perhaps some sort of cheesy filter to enhance sparkle in ring shots.

I've used a polariser and a graduated ND filter on occasion, bit not very often.

In the past, doing "r&d" on new filters, we would try different designs applied to a clear filter with vaseline. Then when we found a design we liked we would copy it using clear nail polish. Most of the time shooting wide open gave the best results.

We have some neutral density filters to help when we're filming outside during the summer, or even in the winter snow, which reflects a lot of light on a sunny day. Actually had one where f/22 was still a little over exposed at ISO100/Shutter 50.

Oh, yes, of course, we use the 8 stop vary ND all the time on the DSLRs…. :)