Multiflash Meteor (Patreon)

One of the Meteor shots. 

One of the techniques is balancing flash with ambient exposure. 99 percent of the time it's during the day, but when you have very long exposures, you can use multiple flash pops to get this. 

So I know my ISO and Aperture and base 20 second exposures for shooting stars in a good dark sky. All you have to do is balance your flash power to match your aperture setting. The only relevance of the shutter is how much background light shows up. In this location, there is one light on a road to the very far left so no effect on flash exposure whatsoever. 

We worked out the movement before the shot. Kate would move once, Kelsey would move two times after the first flash. I was walking around just out of frame on right side, aiming the flash on them from slightly different locations each time. You can see the difference  in the shadows. Manually Popped the flash 3 times for this shot. I would say hold, pop flash, move, hold, pop flash, move and pop last flash. Very fun technique to play with if you have a dark enough location. 

I might try this technique in daytime - I have some pretty dark neutral density filters to get to a 20 second exposure during the day time.