Tungsten to dupilcate Kino?

Daniel Tan · February 9, 2004

Hey there,

Can tungsten lights like Fresenls closely duplicate a Kino flo look on film? Using filters, bounce..etc? How about regular flourescent tubes from Home Depot, they have the correct temperatures(5500K) but I am worried about the flickering effect they have. Can they actually be used?

I am curious to find out.

Thanks

Regards,

Daniel :D

Alvin Pingol · February 10, 2004

>> How about regular flourescent tubes from Home Depot, they have the correct

>> temperatures(5500K) but I am worried about the flickering effect they have.

>> Can they actually be used?

Yes, but require special precautions. Due to the unbalanced (not sure if it's considered "incomplete") spectrum of your standard fluorescent tube, you'll need some CT MinusGreen (Magenta) gels. The strength of the gel depends on the tube. All brands of tubes create their own unique "color," so you'll want to do some tests and be sure not to mix different brands/types of tubes.

Depending on where you are in the world (60Hz or 50Hz mains), you will need to adjust your shutter speed accordingly. In 60Hz territory, shutter angle should be 144 degrees (1/60th sec) to eliminate flicker. In 50Hz, shooting at 25FPS at 180 degrees will make things much easer (unless you want to set your shutter angle to 172.8 degrees, which AFAIK isn't possible ^_^ .)

EDIT: Just saw Mitch's reply in your corss-post. Answers your question about the kino/fresnel.

hugovillasmythe · February 10, 2004

I wouldn't use standard household fluorescents because of the possible flickering, the incomplete spectrum (I'm almost positive they have incomplete spectrums, that's why, when read with a color meter they'll read out weird numbers) and because you hacve to carry a huge ballast everywhere.

A nice way to get soft even light is to get a soft light (like a 4k soft) or something similar or meybe vene use a 5k with a Chimera.

You can even get a great soft source using a 5k and placing in front of it a light box made of white foamcore.

All this options, of course, have pros and cons. The pro is that there is no mistakie possible as far as flicker is concerned and color correction is easier.

Some cons are the huge light demands a 5k or a 4k soft places on a household circuit.

Phil Rhodes · February 10, 2004

Hi,

I've shot copious quantities of video under household fluorescents and their derivatives, and never noticed a single problem. I've done my absolute utmost to create a problem; I have balanced under tungsten light and shot under 3000K fluorescent. I have also manually programmed the CT reading and then shot under fluorescent. I have balanced to daylight and then shot corrected fluorescent. I've never been able to make it cause a problem - and here's the critical bit - while I was using carefully chosen, high-quality triphosphor tubes. I'm not convinced that there's a hell of a lot of difference between what Kino Flo use and the standard household stuff, other than that most good triphosphor tubes are extremely warm.

Flicker is obviously an issue if you are using iron ballasts, but you can buy electronic ones which don't - or, for small tubes, particularly battery-powered ones, homebake your own. I might put together a small-flo ballast guide at some point, it keeps coming up.

Phil

Daniel Tan · February 12, 2004

Depending on where you are in the world (60Hz or 50Hz mains), you will need to adjust your shutter speed accordingly. In 60Hz territory, shutter angle should be 144 degrees (1/60th sec) to eliminate flicker. In 50Hz, shooting at 25FPS at 180 degrees will make things much easer (unless you want to set your shutter angle to 172.8 degrees, which AFAIK isn't possible ^_^ .)

Hey,

Thanks for advising on my question. Sorry but I just want to make sure that I understand this. The shooting at 25fps at 180 degrees in 50Hz - does that mean we do not need any ballast? or is a combination of both that will make it work?

Thank you everyone for posting to my question. I will definitely do some tests and find out more.

Regards,

Daniel

Alvin Pingol · February 13, 2004

You do not need a flicker-free ballast if shooting in a 50Hz country at 25fps (180 deg. shutter), since any flickering of the light that would occur would be synchronized to the camera's shutter.

Michael Nash · February 16, 2004

I've also shot plenty of film and video with household and commercial fluorescent units, but usually FOR their incomplete spectrum. Flicker and color problems are no big deal if you know what you're doing with them.

Off-the-shelf hardware store bulbs do have a little green spike in them, even if the manufacturer claims a color temp of 3200 or 5500 or whatever. The overall color temp may be correct, but the additional green in the tube will need to be corrected out with some minusgreen; usually 1/8 or 1/4. Different film stocks and video cameras will respond differently to the amount of green present.

Flicker is not a problem as long as you shoot at HMI-safe speeds. You don't need a 144 degree shutter at 24fps and 60hz. power -- 24fps (crystal) is an HMI safe speed for all shutter angles.

Also those 4' 2-tube shop lights don't require any heavy ballast; they're self-contained and relatively lightweight (I carry four of them under my arm at a time, and plug them straight into an ordinary Edison outlet). The ballasts do hum a little bit, so I tend to use them only in the background away from dialogue. Sometimes the ballasts can be a little finicky if you cube-tap too many together, but what do you want for less than 10 bucks? ;-)

There are some cool 6500 deg "daylight deluxe" bulbs that give a great blue glow for nightclub interiors and so on. I like to put them behind things and at the base of wall for a little wash or glow on the wall more than incident light.