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Old December 17th, 2004, 01:55 AM   #1
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How To Make Florescent Lights Look Good

I would be really interested to know if anyone has had any experience in making florescent lights look good. I'm talking about the lights you find inside hospitals and classrooms. They make everyone look god-awful.

On rare occasions I see some interesting show where they managed to make the florescents look good without adding additional lighting. I saw this once on a Hospital Reality TV show (not Trauma, Life in the ER, which, by the way, always looks horrid). I also saw a pretty good treatment of florescent lights in an airport in a movie called Love Actually (Hugh Grant thing). They shot on film in Love Actually, except the end where they appeared to briefly switch to video and still made the florescent lights look good.

On the rare occasions when I saw the florescent lights look good, the whites looked blown out, while the midtones brightened but maintained a reasonable amount of detail. I don't know if this is the only way to make florescent lights look good but it's the only examples I've seen.

So, anyone have experience down this path. I suspect it will be a camera plus post-production solution, not just camera alone.

Any help?

Douglas
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Old December 21st, 2004, 05:54 AM   #2
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I've done a search for you on the boards on fluorescent lights,
perhaps there is some more info for you in these threads:

http://www.dvinfo.net/conf/showthrea...threadid=34619
http://www.dvinfo.net/conf/showthrea...threadid=31517
http://www.dvinfo.net/conf/showthrea...threadid=31675
http://www.dvinfo.net/conf/showthrea...&threadid=2203
http://www.dvinfo.net/conf/showthrea...&threadid=2916
http://www.dvinfo.net/conf/showthrea...&threadid=3628
http://www.dvinfo.net/conf/showthrea...&threadid=3980
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Old December 21st, 2004, 01:17 PM   #3
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Rob

Thanks for the research. Unfortunatley only one thread discussed how to deal with flourescents as practicals (you know the flourescent lights you find on site, not the professional color-corrected flourescent lights you bring with you to set up), and even that thread didn't come up with any answers, just a lot of warnings complaints. Most of the other threads talked about using professional flourescents not about dealing with the crappy green and yellow tinged flourescents you find in hospitals and classrooms and supermarkets and almost everywhere else you go.

It's interesting there is no info out there as of yet about this issue, especially considering how prevelant flourescent lights are. I'll start the thread with my finding so far.

I have the XL2 and the custom presets lets me make some correctsions that appear to help the flourescent light problem. It doesn't really totally fix the problem and people don't look awsome, but it does help. Here's what I've done.

1. Turn on cine gamma (I'm still not totally sure turning on cine gamma is the way to go, but it's the way I've gone so far). It appears to warm up the picture and reduce the contrast.

2. Stretch the blacks in order to see more detail in the blacks

3. Turn the R Gain up (add red, reducing cyan)

4. Turn the G Gain down (reduce green, add magenta)

5. Turn B Gain up (adding blue, reducing yellow)

6. Sometimes turn on skin detail to help smooth out the harshness on skin tones.

That's it so far. Maybe there is more I can do in post. Like I said, this is not a total solution but it's all I can figure out so far.

Douglas
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Old December 21st, 2004, 01:43 PM   #4
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<<<-- Originally posted by Douglas Robbins : Rob
1. Turn on cine gamma (I'm still not totally sure turning on cine gamma is the way to go, but it's the way I've gone so far). It appears to warm up the picture and reduce the contrast.>>

Cina-gamma is used to simulte film-like color, i.e. so your video color can look more like film. It's also known as S-Curve.

<<4. Turn the G Gain down (reduce green, add magenta)>>

This is the one that's gonna help. You see there are filters (glass) that compensate florescent unwanted effects (green cast). And they happen to be magenta.

You can also correct the effect in post production using the same principle.

<<6. Sometimes turn on skin detail to help smooth out the harshness on skin tones.>>

You can do that if you want a specific look.

Hope this helps.

Juan
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Old December 21st, 2004, 05:39 PM   #5
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It should be as simple as setting manual white balance under the flourescents. That will work if the flourescents are the only lights. Maybe you are in a mixed light siuation? Flourescents, but with some tungstens lights, and maybe some daylight leaking in from outside? You can't correct for that. You just have to try to control the surroundings.
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Old December 31st, 2004, 09:47 AM   #6
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I used to use 1/2 blue gel on some lights for fill, and try to white balance with a mix of the flourescents and gel'd light. Okay, so I was using more expensive cameras that adjusted better to the color temps, but it worked well.
Haven't tried this on any DV cam however.
The flourescent light is somewhere around 48k color (greenish) and the 1/2 blue will look a little warmer.

my 2 cents.

Jeff P.
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Old December 31st, 2004, 11:39 AM   #7
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Standard (cold) fluorescents contain phosphors (for efficiency reasons) which don't show a smooth spectrum. More specifically they "peak" in a small part of the green/yellow spectrum region which makes it impossible to correct by whitebalancing. Reducing the green component in post will sometimes partly solve the problem (if one can accepts a somewhat slightly magenta like white reproduction). Reducing the green chroma component (G-Y) w.r.t (R-Y) and (B-Y) would be OK w.r.t. WB, but still will compromise some colors. The only correct way to go is to "smooth' the spectrum hitting your CCD by an optical band supression filter. This filter reduces the specific spectrum part of fluorescents and looks magenta.
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Old January 1st, 2005, 10:48 PM   #8
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Douglas,
My method for dealing with fluos is to balance them to the key light source. To do this without replacing the cool whites with tungsten or daylight balance tubes, I put in the apropriate level of Minus Green gel (made specifically for this purpose). That will take the green out without modifying the color temperature. There are also variations of Minus Green that correct cool white fluos to match tungsten or daylight, however you may loose up to a couple stops depending on the intensity of the gel. If the fixtures are in the shot, I may use a clear plastic sleeve that goes around the tube with the gel in it. (but I usually just use color correct tubes in order to avoid the hassle) If you're in a place like a supermarket where fluorescents are the dominant light source, just white balance. Those places usually have very heavy ND on the windows so incoming daylight won't really have a big effect.

Another thing I do is put 216 diffusion on the fluo fixture whenever possible. A fluorescent tube casts the same type of shadow as a soft white light bulb: both are coated with "diffusion" inside the bulb, but they still cast a hard shadow (which is a major reason why they make people look so bad). Flouresents can look beautiful when well-diffused because the result is an ULTRA-soft glow that can wrap around a face if the source is big enough.
For what it's worth, my go-to soft key light is a home made fluorescent soft box.

I personally wouldn't tweak the master color settings in camera or try to take out the green in post because where there are fluorescents, there are often other types of light sources. Messing with master colors may throw off how those other sources read.
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Old January 2nd, 2005, 10:45 AM   #9
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Turn them off. Move over by a window and use a reflector. I've even left them on for office portraits and the light coming from outside seems to override the office lights.
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