Here is the easy/important part.
Use the table on the back of the "flying camera" to get the proper exposure time. Just use the number that the needle reads to find the time.
Example: If the light meter needle reads 5 then you open the shutter for 161.28 seconds.
Note: If you are taking a photo of a person, that person has to be still for that amount of time to be in any kind of focus.