They brought a gnomon, with a color chart, on the Apollo missions. They would set it up for many of the pictures of samples. https://airandspace.si.edu/collect

They brought a gnomon, with a color chart, on the Apollo missions. They would set it up for many of the pictures of samples. https://airandspace.si.edu/collection-objects/gnomon-lunar-apollo/nasm_A19810890000 https://airandspace.si.edu/collection-objects/gnomon-lunar-a...