ARRI MB-14

Description

ARRI MB14, complete Mattebox

Maximum filter size: 6.6″ × 6.6″ (square trays) OR round ø 6″.
Standard configuration: 4-filter stage (for four 6.6″×6.6″ push-through filters) in the base kit.
Other filter stage options: you can swap in 2-filter stages or mix with 4″×4″ trays and/or 138 mm round filters.
Swing-away front: the matte box swings open 90° to the front for easier lens changes.
Lateral adjustment via quick-set clamp on the side.
Minimum focal length coverage: With the wide “MB-14-W” carrier, it can cover down to ≈ 9.8 mm; with the standard carrier ≈12 mm.
- Specifically: “Min focal length 9.8 mm (with MB14W) / 12 mm (with MB14)”.
Dimensions: 372 × 260 × 155 mm (L × W × H) approx.
Weight: approx. 2.45 kg (≈ 5.4 lbs)
Support/rod requirement: Designed for use with 19 mm or 15 mm studio support rods / bridge plate.
Flags & accessories: Comes (or common kit includes) top, bottom and side flags, French flag holder, masks for different lens focal lengths.

Because of the large filter size (6.6″ × 6.6″) and robust construction, the MB-14 is more suited for studio or heavy duty production rigs, rather than lightweight handheld / run-and-gun setups. (As one user noted:

“It did work nice for handheld, it’s more weight but solid to hold on to.” )
The “MB-14-W” wide carrier variant is specifically for ultra-wide lenses (down to ~9.8 mm). If you have very wide primes, you’ll want that version.
Filter stack depth: The front 4-filter stage has a rear receptacle that accepts e.g. 6″, 138 mm or 4½″ round filters, plus additional smaller filter stages. This means you have flexibility in filter types, but also increased depth and potential for vignetting if not set up carefully.
When using smaller front lens diameters or formats, you may need adapter rings or reducer trays (for smaller filter sizes) so that the MB-14 can be used without vignetting. The manual cautions: “Rings can vignette. Please contact ARRI.”
Because of its size and weight, if you mount it on a lighter camera or use handheld, you should balance for the extra front-end load (filter trays + matte box).
Although it says “discontinued items only as long as stock is available” in the documentation. So availability/accessory support may be more limited compared to newer matte boxes.
Ideal for large format lenses, studio rigs, zooms, wide-angle large diameter lenses.

If you are using large format or large diameter cine lenses (e.g., 95mm+ front diameter or ultra-wide primes) and want the flexibility of large square filters (6.6″×6.6″) then MB-14 is a strong pick.
If your workflow is lighter (handheld, mirrorless, small form-factor) or you only use smaller filters (4×4″, 4×5.65″), there are lighter matte boxes more suited and the MB-14 might be overkill (and too heavy).
Because the filter tray size is big, the cost of filters (6.6″×6.6″) will be higher than smaller size trays — something to budget for if you’ll use that size.
Ensure your support rods or bridge plate system can handle the size/weight and that you have enough clearance/space for the front of the matte box (372mm length) especially in tighter rigs.