How many lumens to film video in a cave with a GoPro?

[kensuf]

"It depends"

If you're trying to get video of large-ish rooms/tunnels, put bright lights on the models up front, but keep lower powered lights near your camera. If you try to run high power lights right next to the camera you'll get a lot of color distortion (blue backwash, etc). I have a set of two 9000 lumen Big Blue lights, that I can strap on a buddies scooter and run at full power while using two 8000 lumen big blue lights at 1/2 power next to the camera. The 9000 lumen lights are NOT enough, I have other friends that are using twin 15,000 lumen lights (both Keldan's and Big Blue) with much greater success.

Also, shoot in flat mode and tune colors in post-prod.

 

[CaveSloth]

I was hoping to go with a rig like this and mount 2 of the 2600 lumen BigBlue "black molly" lights on it. (replace middle light in pic with gopro)

 

[CaveSloth]

BigBlue Black Molly is 2600 Lumens with a 120 degree beam angle. I am going to try 2 of them on either side of the GoPro, behind the plane of the GoPro, angled outward so that the light overlaps a few feet in front of the camera and see how it goes.

 

[tursiops]

I was hoping to go with a rig like this and mount 2 of the 2600 lumen BigBlue "black molly" lights on it. (replace middle light in pic with gopro)

View attachment 550613

You've been told several times NOT to do that. Get the lights away from the camera position. Light mainly the walls and background, secondarily the diver(s).

 

[CaveSloth]

You've been told several times NOT to do that. Get the lights away from the camera position. Light mainly the walls and background, secondarily the diver(s).

Well having the lights behind the plane of the camera and angling them out should help, no?

 

[CaveSloth]

I understand what is being suggested for professional video lighting. Perhaps I should have been more specific in my question in relation to the planned apparatus.

 

[tursiops]

Well having the lights behind the plane of the camera and angling them out should help, no?

No.

 

[CaveSloth]

Ok, well, it's just not feasible for me to set up lights and then dive and film and then go back and pull the lights out. I need something I can hold in one hand and deploy and stow while diving.

 

[CaveSloth]

By the way, I have gotten decent results using a single BigBlue video light with the GoPro mounted ON THE LIGHT. But there is a ton of backscatter. I think having two lights even a few inches away, angled out, behind the plane of the camera will create a dark space in front of the camera and reduce backscatter.

 

[tursiops]

Ok, well, it's just not feasible for me to set up lights and then dive and film and then go back and pull the lights out. I need something I can hold in one hand and deploy and stow while diving.

At the very least, give one of those lights to the diver-subject-model and have them shine it on the wall behind them.