A highly polished, reflective stainless steel sphere resting on a cloth outdoors.

Industry Article

What a VFX HDRI Chrome and Grey Ball Set Is Used For

Why a reference ball is a measuring instrument, which diameters crews actually buy, and what separates a production ball from a garden ornament.

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The Ball Is Data, Not Decoration

On set, a chrome ball captures the environment as a reflection and a grey ball captures how light falls on a neutral diffuse surface. Both are then used to reconstruct the lighting in a scene so that a computer generated element sits inside the plate rather than on top of it. That makes the ball a measuring instrument, and a measuring instrument that is not accurate is worse than none at all.

Side-by-side comparison of a matte grey sphere and a polished chrome sphere mounted on stands outdoors. — Chrome and grey balls on threaded mounts, the pairing most crews shoot together.

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Why a Garden Gazing Ball Does Not Work

A decorative sphere is polished to look good, not to reflect accurately. Small waves in the surface distort the environment map in ways that are hard to spot on set and painful to correct in comp. Our VFX spheres pass through more than twenty surface processes specifically to hold a clean specular reflection, and the grey has been set through repeated post production testing rather than picked by eye.

Which Diameters Crews Buy

We make 6 cm, 12.6 cm, 20 cm, 25 cm and 30 cm. 20 cm and 25 cm are the common working sizes and cover most set ups. 6 cm and 12.6 cm suit tight interiors and travel kits where the ball has to fit in a camera case. 30 cm is for wide exteriors where the ball still has to read at distance.

A polished chrome sphere and a matte gray sphere mounted on a tripod outdoors. — A 20 cm grey ball. Neutral grey is what keeps the lighting solve from drifting in grade.

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Half Chrome Half Grey

When there is no time for two set ups, a half chrome half grey ball puts both references in one frame. We make these in 25 cm among other sizes. Crews that shoot long days with fast turnarounds tend to keep one in the kit alongside separate full chrome and full grey balls.

Mounting and Handling

Threaded mounting lets the ball sit solidly on a stand, a magic arm or a tripod head, which matters because a ball that shifts between takes produces references that do not agree. Keep the protective film on between shoots and handle the chrome by the mount rather than the surface.

Buying a Set

Order chrome and grey together so they arrive as a matched pair and are shipped in the same batch. Sets are foam packed with the protective film left on the chrome surface. Lead time is 15 to 30 days after the deposit is received.