What are these archeological reference plates called?

Factual Questions
1

From this article: Thousands of cave paintings have been discovered in Mexico

The photos have black and white or color rectangles used as reference to color and scale. What are they called?

2

Kodak call the colour one “Colour separation guide”.

They sell a greyscale control … the black and white ones seem primitive.

http://motion.kodak.com/motion/Products/Lab_And_Post_Production/Control_Tools/KODAK_Color_Separation_Guides_and_Gray_Scales.htm

3

In archaeology, I think they are called photo scales. Similar ones are used in forensic photography.

4

Not really - they provide a very crisp and clear size indication in two dimensions. They might be primitive in other forms of photo correction, but for archaeology you only need a color palette and a sizing guide. Grayscale would be of no real use and could be more difficult to measure.

5

Thanks y’all.

6

I use a Macbeth Color Checker in my small product photography set up shots. With a monitor calibrated properly, I can make sure the item looks realistic after image processing. Somewhat similar idea, slightly different tools.

7

Interestingly enough, some space craft and rovers have color checker plates on them. I saw one on some rover at the Kansas Cosmosphere. Makes sense, too … by aiming the camera at the color plate (which is a known entity), they can get a good idea of the color/reflectivity of an object that is being viewed through various imaging devices.