I'm currently building myself a mattebox, a proper one, not the Cokin one I've done for the HV (which still serves me well, with the HV!).
I think I've figured out a way to put the flags on it, sides and top, but what's really bugging me now is the filters holder (or filterstages). I'm not using 4x4 filters (100mm), but Cokin filters, which are 84mm instead. That's not much of a problem as I'll be using the filters on prime lenses, not wide lenses.
Now I need to design a way (convenient one) to put on & off the filters without being too much trouble to do such. The Cokin holder is nice as the filters slides in it and holds by pressure, but I would like to build one that would be more robust in the construction.
I'm looking for ideas, if you have some, I'm all ears!