800 fps, exterior, moonlight, rain rig.

[Jean-Marc Plante]

Hello fellas!

 

Will be DP on a shoot with friends soon for a videoclip.

We have about 40k budget, and we wanna try something new, therefore I'd like some advice!

 

We're gonna shoot on a phantom 2.5k, Prores 422, slow-mo shot of gunfire on a single man.

 

My mentor, an experienced DP, suggested I should not touch any HMIs at this speed, and stick to 5k tungsten scoops and above, as anything under will start flickering (black bodies cooling too fast)

 

This is gonna be shot in a cemetery, therefore we will be using a geni, I thought we would have more then enough with a 300amp.

 

As for the look, I wanna make it look like it is moonlight, without feeling the source. I thought going too strong on CTB would cut too much light, and so not got any further then 1/2, balance the white on the camera accordingly, and blue it up in post.

 

What kind of diffusion should I Use? Should I stick to 4x4 frames, get those close to the source and protect them using heatshield? And am I better of using Crinkos or a crane, literally, to hang those light sources. Looking for the cheapest alternative that still gets the job done.

 

Any good tips for outdoor moonlight lighting, or anything shot at this speed, will greatly help me in my prep!

 

Thanks!

[David Mullen ASC]

You need a TON of light for 800 fps -- that's like a 5-stop light loss to compensate for -- so I don't think a 300A genny is going to cut it, not if you are trying to light a background at night. Maybe you should consider side-lighting everything for moonlight and rake the background (if something like a row of trees fifty feet away) with something like a 20K and key the actor closer with a 10K, fill with a bounced 5K, etc. That's over 300A right there...

 

Think about it, if you lit your night exterior to f/16 for 24 fps, you'd be shooting close to f/2.8 at 800 fps.

[Freya Black]

Maybe you could shoot day for night in this context??

 

Freya

[Guy Holt]

You need a TON of light for 800 fps .... so I don't think a 300A genny is going to cut it, not if you are trying to light a background at night. Maybe you should consider side-lighting everything for moonlight and rake the background (if something like a row of trees fifty feet away) with something like a 20K and key the actor closer with a 10K, fill with a bounced 5K, etc. That's over 300A right there...

 

+1. Given your frame rate you will need some sizable fixtures and a sizable distribution system to power them. Whatever fixtures you decide to use be sure to use GFCIs on all branch circuits supplying your lights as well as your main feeder trunks. GFCIs are a must when working around water in order to avoid someone taking a potentially lethal shock. For tungsten heads larger than 2kw you will need film style GFCIs, like Shock Blocks, that are specifically designed for high amperage motion picture lights. To prevent nuisance tripping while providing Class A protection for your crew you should use an interlocking zone system approach of both Class A and Class C GFCIs.

 

If you want to learn more about ground fault protection in wet situations, I have made available online an IATSE training curriculum that I developed for Local 481. It covers ground fault protection for everything from battery boxes to Crawford Studio generators. You will find it at this web address: http://www.screenlightandgrip.com/html/481_GFCI_Workshop.html

 

Guy Holt, Gaffer

ScreenLight and Grip

Lighting Rental & Sales in Boston

[Jean-Marc Plante]

Guy holt, this is an Adamant point you just brought to the table. Thanks.

 

I think the plan is drastically changing now though. Will need to talk further with the Director.