A Discussion of the types of Matte Boxes for tric effects are lens shade produced by Bolex.
Guide to Matte Boxes
Why Eiger Matte Box? Eiger Matte Box system resolves the frustration of using filters without a matte box. It incorporates optional filters (VND, Gradient, Mist, Steak, Straight ND) in one system. The adjustable carbon fiber top flag minimizes glare or flare for superior image quality. Diverse integration: The Eiger Matte Box system is compatible with insert filters and magnetic or threaded filters.
Freewell Eiger Matte Box with Clamp-On Matte Box Optional Lens
SmallRig Mini Matte Box Pro and Lite Released
Using a Matte Box on the GH1
Tilta Mirage VND Matte Box Review - Paul Joy
Tilta Matte Box review - good stuff from China? - Dan McComb
Shape Cage with Top Handle, 15mm Baseplate, Follow Focus & Matte Box for Sony a7S III
PROAIM MB-600 Camera Sunshade Matte Box
Matte Boxes and Lens Hoods can make your pictures sharper, also a look at the Alphatron Matte Box.
SmallRig Professional Cage Kit with Matte Box Follow Focus for Sony A7S3 Camera
CineMorph Matte Box Anamorphic Looks Filters — Vid-Atlantic Media Productions
Matte box - Wikipedia
SmallRig lightweight Matte Box review: Simple and to the point
