Luminance/Reflection Ball on stick thing

[Julz-Rulez]

Hey I was just wondering what you call those balls on stick thingys they use to test luminance and reflectivity when doing a vfx shot. I've been trying to search them up but have found nothing.

[Reddkryten]

They are called light probes.

I hope you don't mind me going slightly off topic, but I have a similar, obscure FX question.

Does anyone know the name of a grid used in computer graphics? It looks sort of like the grid on the holodeck in star trek.

I was watching the DVD of Batman Returns and they had live penguins standing in front of the grid, they then use the images to measure the size and shape of the animal and turned that into a 3d model.

I think a similar grid was also used in Eadweard Muybridge's walk cycles.