Matte boxes Clamp On Vs rod supported.
 

My ideal matte box will most likely be a Chrosziel , but the price of a set of rails is a killer.

I'm concerned that the threaded adapter for the VX2K, the 58 mm thread to 85 mm cone , will be prone to being unstable. I can envision the matte box rotating as the adapter comes loose on the filter threads. I'm also cocerned that the bayonet mount on the Optex Wide Angle may also come loose when the matte box is clamped to it.

The century has rails , but both filter stages rotate together ( a major inconvenience). The Cavision mattebox with rails is cheaper but it doesn't have a 4x5 or 4x6 frame for grads.

Another possibility is if the cavision rails fit the Chrosziel.

Any comments will be appreciated.

When I get done I will write up a buyers guide to matte boxes.

Bryan,
FWIW, I have a Chrozsiel and use the screw-on lens adapter with my XL1S. I haven't found the interface between the 72mm-85mm adapter and the mattebox unstable at all. It easily secures well. Not to say that it couldn't be bashed out of position, but it's unlikely to happen under proper use.