I can think of two of them:
-- carbon monoxide
-- black soot
Answer: SATURATED
Explanation:
When a solute can no longer be dissolved it is considered "saturated" as is.
A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.