View Full Version : Low cost, effective fake TV flicker


Josh Bass
December 23rd, 2003, 03:58 PM
Ok, so I want to simulate the light of a TV on someone's face as they watch. How can I do it and make it convincing, cheaply? They'd be watching a movie they just made. . .if that matters or helps.

Kris Carrillo
December 23rd, 2003, 05:14 PM
it depends on the shot size. for a close-up, the easiest most effective way i can think of would be to buy two small flourescent lights and gel them to taste. then i would use both the flo's to key the person's face and move around a cookie in between the actor and the lights. obviously, this will take some experimentation to get the desired effect. additionally, i would also toggle each of the lights on and off randomly to further simulate the effect of cuts in the footage he is watching. good luck,

kris carrillo
WCTV 56

Imran Zaidi
December 23rd, 2003, 06:15 PM
I recently worked on a project where we had to do something like that, but needed to do it quickly, without any special equipment. So this is what I did, and the end result worked perfectly. It was supposed to be a guy watching TV on a couch during twilight outside. We were NOT pulling audio for this take, and this solution probably won't be right for you as it makes some noise that a good boom would pick up all too well.

- I used only one source of light - a light placed where the TV would be
- Color balanced to make things a bit blue (tv light always seems to look more tv-ish when a little bluish)
- I told an old piece of crinkled up gel and cut strips like a curtain on one side (I didn't cut off the pieces - just made tentacles, basically)
- I held the cut up gel in front of the light and crinkled and moved it around erratically.

It sounds really ghetto, but the end result was perfectly fine, and unless you were there, you would never know it wasn't a TV.

Zac Stein
December 23rd, 2003, 06:28 PM
Heres an idea, USE a tv near the actors face? wouldn't that give you tv style lighting?

heheh actually i am joking,

when we did it, we were lucky to able to borrow a cheap crappy LCD projector off someone, just plugged it into a tv tuner and then blurred the thing and turned it's light level down and faced it as the couch, instant TV look.

Zac

John Locke
December 23rd, 2003, 06:54 PM
I wonder though...wouldn't a TV work? Put in a tape of "War of the Worlds" or "Star Wars"...something with lots of laser battles...and turn up the brightness.

Rick Bravo
December 24th, 2003, 12:32 AM
John, the TV would not work as it is not strong enough to put out the amount of light you would need to create the flicker effect you are looking for. I think that the effect Josh is looking for is the TV flicker in a darkened, but not totaly dark room.

Imran is solidly on the right track. TVs are closer to 5600 degrees Kelvin or Daylight and would indeed look bluer in relation to typical house lighting which is generally in the Tungsten or 3200 degree Kelvin range. By the way, Imran, in Miami, things get "Carribeanized" as opposed to Ghettoed!

When we shoot a TV using film, usually the film is an indoor film or Tungsten balanced. The TV is gelled with a 1/2 85 gel to bring the temp down but still retain some of the blue that is associated with a TV in a dark room.

Zac's idea of a pojector seems pretty legit and probably very effective. I have never done it but it seems like the way to go as the projector has the intensity, can be color corrected with gels, you can control the spread of the light, and you can just play a movie through it for random flicker...I wish I would have thought of it!

Happy Holidays to all, RB.

Josh Bass
December 24th, 2003, 03:28 AM
I think either the flo idea or the ghetto waving of a gel in front of a light will be the answer. Thanks.

Charles Papert
December 24th, 2003, 05:01 PM
Josh:

I had this come up in an Instant Film last year and had to make a solution on the spot which was even more "ghetto" than cutting gels!

I took a 650 open face with full CTB (I agree with Rick and Imran that a daylight blue (5600) unit shot in a tungsten balanced environment is most realistic) at medium spot and aimed it into a bounce card which faced the actors, at about the same height as the TV set. Then I simply panned the unit on and off the card in a mechanical and erratic fashion. This created a simple intensity shift. It's good to play around with the technique so that it isn't overdone. Think about the material that is being viewed--does it have a lot of cuts? If so, you can make the intensity shifts more frequent. But if it's a program that has shots that linger on for a few seconds, you might want to duplicate that feel by only making shifts occasionally.

In "Dougie Dangerous" (http://64.235.253.222/archivenew4.htm#003), the Instant Film where I used this technique, I actually operated both the effect and the camera simultaneously (because of time constraints and minimal crew, and I probably enjoyed the challenge!). As a result, you can see that the effect doesn't start after the camera tilt/zoom ends, since I needed both hands to make the move. This take also looks like I was being extra-conservative with the effect, so there are only a few intensity shifts represented. It's on the verge of being perhaps too subtle, but at least you can see what this approach can do.

Naturally, what is "right" or "real" is subjective, and has a lot to do with the emotion of the scene--it may feel better to have a more frantic effect, or more stylized.

p.s. apparently the current state of our archives is this: If viewing on OSX, use Explorer as Safari doesn't seem able to access the archive. The TV effect appears in the last scene as the four characters watch "The Lion King".

Robert Knecht Schmidt
December 24th, 2003, 09:38 PM
I've never liked the switcher/fader solutions because their effect is never really convincing: the fades are graduated and non-random, and devoid of the step functions (http://mathworld.wolfram.com/HeavisideStepFunction.html) that typify television broadcasts. (That is to say, in real TV, the picture tube cuts instantaneously from bright white to dark black every few seconds.)

Here's a solution that will produce a more accurate effect should you have a video projector and an extra VCR at hand. Create a video clip of random, quick bright-blue-to-black cuts and rapid fades, then run this through the projector. Point the projector at your subject, and set the projector's zoom lens to ultra wide. Then play the tape of your fake TV emission signal through the projector, and voila!

Charles Papert
December 24th, 2003, 10:53 PM
Well, in the interest of providing my usual "don't know if this of use to anyone here, but this is how it would be done in the industry" sort of thing (which I can justify since I gave a low-tech solution above):

On "Mr. 3000", the Bernie Mac movie I worked on last summer (I'm guessing we'll start seeing Coming Attractions for it after the holidays), DP Shane Hurlbut had the gaffer rig up an interesting gag for a scene in which Bernie watches TV in his house. It consisted of 3 diffused bulbs in a housing, each colored with either red, blue or green gel. Each bulb was fed into a random flicker generator box set at different rates. Thus the color and intensity was fully random, and the intensity shifts were rapid as if motivated by cuts as Robert and I have recommended. Nice setup--possibly overkill though!

Josh Bass
December 25th, 2003, 01:43 AM
What about getting a couple of Home Depot plug-in flourescents, putting them in front of/taping them/whatever/ to the TV and plugging them into power strips. . .? Alternately clicking on and off the different lights, using the toggle on the power strip?

Charles Papert
December 25th, 2003, 07:49 AM
Usually there is a delay when you switch on a fluorescent, and they can be unpredictable. Of course, this might add to the randomness in a good way--but then again it might not! Could work, though. You'd want at least three to keep the effect from being repetitive.

Josh Bass
December 25th, 2003, 11:38 AM
Grrrr. . . thou art right.

Brian T. Young
December 25th, 2003, 10:14 PM
magicgadgets.com have random flicker generators with presets for fires, tv, movies, etc... but you have to have the budget for em. nice pieces.

Scott Spears
January 16th, 2004, 07:41 PM
I do it the old fashion way. I set up two lights, 650 watt fresnels with some diffusion and 3/4 blue gels (sometime full blue if I'm feeling crazy). Then I take a copy of finger flags and wave them in front of the lights randomly. I tried a flicker box, but wasn't happy with the look.

I do the same with fire, but use orange, red and yellow gels on multiple lights.

Hey, it gives the grips something to do and keeps them out of trouble.

Josh Bass
January 16th, 2004, 11:36 PM
Thanks guys. I have, however, been blessed to make an arrangement with a local studio to borrow their gear whenever, as long as I give them a heads up and treat it nicely. Consequently, I now have in my possession a 2k zip light, and a 1k dimmer (I'll only use one of the 1k bulbs in the ziplight), and a few other things.

I think if I had to do it with the gear available to me that I own, I would have, like some of you, just waved something in front of a gelled light. . .looked pretty good when I was screwing around.

K. Forman
January 17th, 2004, 06:10 AM
What about taping a string of blue and white blinking christmas lights to the front of a tv? If they blink fast enough, it seems like that might work?

Josh Bass
January 17th, 2004, 11:05 AM
Yeah, but it'd be over the top, I think. One of the things this DP friend of mine told me is that people overdo the effect too often--making these crazy flickers when they're supposed to be watching something calm. The flicker should come from when the picture on the TV allegedly changes significantly---so if you're watching a music video, then it'd be crazy, but if it was a narrative piece (sitcom, drama, movie) then the cuts would only come every few seconds, maybe. Kind of a randomized pattern is what you want.

Scott Spears
January 17th, 2004, 11:30 AM
You're right about the frequency of the flicker. Don't over do it. The light changes are motived by what ever is on the TV, so unless the character is watching MTV or something else with fast cuts, then the flicker should be infrequent, like once every 3-6 seconds.

One night I was walking down the street and looked up at a window (Hey, I'm not a peeping tom), and saw the flicker of a TV and noticed that the shadows from the flicker actually changed positions, as if it were two light soucres. It must have been a big TV, 27' or better and whatever they were watching had compositions with lots of contrast. It was like half the screen was bright and then on a cut it switched, thus causing the shadows to shift, just like if you had two light souces going on and off that were a foot or so apart.

Sorry to babble on, but I would have never thought of it unless I saw the effect in real life.

Scott