Good filter to use when shooting indoors? greenscreen?
 

Curious if there are filters for indoor shooting -- I've used polarizers and black mist when outdoors and like the results. Are there filters that could improve contrast or color when shooting under artificial light?

Also, we shoot a lot of greenscreen now. Anyone use filters to help that along?

There is an ultracon filter by Tiffen in 4 x 4, which will slightly bring up detail in a blacked out area like a glass fronted cupboard.