Slow motion lighting

J. Scott Portingale · May 13, 2009

I'm an independent filmmaker that wants to shoot slow-motion on film (most likely 16mm 1000-2000 fps) in a studio environment, and was wondering what is the best, and the most economical lighting source would be to avoid flicker. Kino flows?

jeff woods · May 13, 2009

Do you mean "economical" in the monetary sense, or power-consumption sense?

Chris Keth · May 13, 2009

Do you mean "economical" in the monetary sense, or power-consumption sense?

I'm pretty sure that way up in those kind of framerates, large tungsten units are the only choice. There are a few people here (Kevin Zanit being one of them) that do a lot of high-speed work and they can tell you for sure, but I think you're looking at 10Ks. Even 5Ks probably flicker at 2000fps.

Edited May 13, 2009 by Chris Keth

J. Scott Portingale · May 13, 2009

It's funny you mentioned Kevin, because we just had a message exchange a few hours ago in the visual effects forum pertaining to frame rate/shutter angle exposure relationships. He used large tungsten lights for his slow-mo work which I don't have access to on my budget. I do have access to HMIS (on a discount), but I'm not sure how they will work at frame rates over 1000fps. I think I'll start sourcing out 5ks and 10ks and pay the extra. I don't want to risk having poor results.

Kevin Zanit · May 13, 2009

This has been discussed quite a lot in the past, please do a search.

The short answer is the cheapest light source for these frame rates would be the sun.

In a studio setting you need to use either Tungsten lights that are 5k or bigger. Smaller sources will flicker. You can use HMIs. Personally, I have had mixed experiences with HMIs. Sometimes you will get flicker/ arc wonder (these are two different things, but both can happen at these frame rates). Lightning Strikes Softsuns have worked very well though (50k and 100k units).

What 16mm camera would be using that could shoot at 2000fps out of curiosity? Most film cameras will be a bit more forgiving about flicker because there is no pin registration, etc which means there are typically so many other problems with the image you don't notice flicker.

Scott Fritzshall · May 14, 2009

I'm not an authoritative source, but I'm pretty sure that there are no 16mm cameras that will do 1000fps. I think you'll be limited to specialty cameras like Photosonics or Phantoms. Those will probably eat up your entire budget as well, so you'll probably have to shoot outdoors at noon or something, since 1000fps would require an additional 5 stops of light.

J. Scott Portingale · May 14, 2009

A friend of mine owns a photosonic that shoots 1000fps. It was previously used in the military, and for automotive crash test scenarios.

Thanks for the info I'll find a 10k after testing it useing the sun.

Mark Dunn · May 14, 2009

You will find daylight quite limiting at that framing rate. Remember your slowest shutter speed with the 1B is 1/5000sec. With 400ISO that's about f/4. Depending on your field of view I suggest you're going to need at least a couple of Blondes.

FYI a number of 16mm rotary prism cameras go to 10,000pps- the Hitachi, the NAC E10, the Fastax 2- and the various Fastax 1s with no speed regulation will manage about 6000.

With pin registration you're really limited to the Locam or the 1PL at 500.

Of course you need double-perf film.

Scott Fritzshall · May 14, 2009

That will teach me to post before looking it up. I checked out Photosonics site and, man, 16mm cameras can go really fast! Never would have guessed!

Hillary Knox · May 14, 2009

In a studio setting you need to use either Tungsten lights that are 5k or bigger. Smaller sources will flicker.

Just out of curiosity, why will sources smaller than 5k flicker?

Kevin Zanit · May 14, 2009

Again, the topic has been covered a bunch by a lot of people so please do a search.

The flicker with smaller tungsten units is because on AC power the 60Hz cycle causes the filament to heat up and cool down. With smaller globes the filaments are small and thus cool down much quicker, so you actually see the filament turning on and off at those frame rates. With bigger globes (5k and up), the filament is so big that it cools down much slower and thus appears continuously on in spite of heating up and cooling down at 60Hz.

On DC power none of this is an issue.

Mark Dunn · May 15, 2009

I never noticed serious flicker from Blondes or other 1 or 2K sources, even at 10,000pps.

Mark Dunn · May 15, 2009

That will teach me to post before looking it up. I checked out Photosonics site and, man, 16mm cameras can go really fast! Never would have guessed!

Drum cameras ran up to a couple of million fps, although with stationary film and one lens per frame, the image being reflected off a mirror spun up to a similar speed with compressed air.

The practical limit for moving film is really about 10,000 fps, or 20,000 using a half-height frame. 16mm. being less massive will go quicker. The limiting factor is really how fast you can run up to speed, and how much film is left when you've done it. Even at 5,000fps which is really the limit of my experience, it takes about as long to run a 400' spool as to say 'high speed cine is very expensive'.