All you have to do is basically as you said, drop the e in exposure and add -ure to the end.
Exposure
Technically it is true that Frederick Scott Archer introduced the concept of combining artificial and natural light in the studio, but it should be noted that this concept had been used before, just without much fame.
1. *also keep in mind that your first paragraph/ sentence in a excerpt will be your main idea*
The answer: is understanding