Simplify the following text for a Grade 9 native English-speaking person.
Original: When the original reference beam illuminates the hologram , it is diffracted by the recorded hologram to produce a light field which is identical to the light field which was originally scattered by the object or objects onto the hologram .
Simplified: The process of creating a hologram is nearly identical to photography through diverse chemicals . To look at a hologram just recorded , you have to light the film with the reference wave .