When supervisors are on-set shooting and need good reference they often use lighting checkers that gives consistent reference of how the scene is affected by the different lighting conditions from shot to shot and scene to scene. Akromatic has released a variety of gray and chromatic spheres in different configurations for this use with the latest one named “Tiny”. The name was chosen because of its size and portability. “Tiny” contains two spheres, one gray and one chromatic and both spheres are 9cm in size (it isn’t specified if this is in radius or diameter).
The spheres they sell are are handmade and as a result they may have slight imperfections in paint and finish but Akromatic assures that these imperfections do in no way affect their performance. Also worth noting is that these spheres are not designed for HDRI photography.
Take a closer look at Akromatic’s website.
“it isn’t specified if this is in radius or diameter”
You can easily figure this out by looking at the rest of the specs they list along with the sphere sizes, and then look at the image again.
Size of the spheres: 9 cm
Size of the carbon fibre handles: 7cm <— use this for scale
Tripod support: 20cm (includes 3/8 adaptor) <— or this
Now how big do the spheres appear to the carbon fiber handle?