The RED One camera uses a 35mm Academy-sized sensor. This means that it uses 35mm format lenses, which can often require a physically large mattebox in order to shade and filter the glass. For most prime (fixed focal length) lenses, a 4×5.65 inch filter will fully cover the lens, but if a large zoom or a rotating filter such as a grad or a polarizer is used then generally a 5.65×5.65 inch filter may be required. For very large lenses, a 6.6×6.6 inch filter may be necessary.
Most matteboxes hold at least two filter trays. Many are available with stackable stages that can be expanded to hold three or more filters. The rear bellows section which mates with the lens itself often has a circular retaining ring within to hold a round filter in either 138mm or 4.5 inch (114mm) diameter. Some matteboxes can also hold a filter in the “suicide stage,” which is a clip in the front shade itself. The standard stages often are rotatable, sometimes each of them individually.
Matteboxes can mount to lightweight 15mm front rods, 15mm sliding baseplate (studio) rods, or 19mm sliding baseplate rods. A mattebox that mounts to the lightweight rods can be mounted to the other styles by use of an adapter, which on some models is specifically designed for that mattebox. Some small matteboxes mount directly to the lightweight rods and do not have a mechanism to swing the mattebox away from the lens during resets. All larger studio mount matteboxes can swing away. Some very small matteboxes can clamp directly onto the camera lens, but this will limit their functionality.
Matteboxes can use various rings to fit to various sized lenses. On the front of the mattebox there can be added extension wings to block stray light on the top, bottom, and sides.