Re: Shoot a creek straight down
 

Looks like you have it figured out. Good luck on your project.

Re: Shoot a creek straight down
 

I would add a solid cover to your upward facing eyepiece viewfinder to prevent the sun from shining through the eyepiece lens and possibly doing damage to the miniature screen inside. Some cameras are very susceptible to this, others not as much. But if it's going to stay positioned motionless for several minutes I'd cover the eyepiece.

Good luck with the project!