Thursday, October 07, 2010

Rosco will Help You Correct for Those Screwy Fluorescents

Time was, things were simpler and fluorescent lights only required a 30CC magenta filter in front of your film-based camera lens to bring them into line. Green your flash and you were done. Then the hippies took over and now we have CFLs pretty much everywhere. And they are not all the same color, either.

Today, Joel Svendsen (who is not a professional actor but merely an ordinary person much like yourself) will walk you through how to correct for the various types of fluorescent lights.

It is geared towards video but you can translate pretty easily. The big difference is that video folks frequently work with tungsten lights. Or as they apparently call it, a package.

But thanks to Joel I shall henceforth think of warm CFLs, for instance, as sort of a weird combo of tungsten and fluorescent, both of which need to be fixed.

Joel, BTW, is the man at Rosco behind the Strobist Collection gel pack -- which also saved the gel sample program from certain death. And that means that he drinks for free in Baltimore, whenever he visits.



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Blogger ALok said...

This seems to not address the most important types, the most common CFLs I encounter are 2500-2700K, which seems warmer than any other light.

October 07, 2010 11:40 PM  
Blogger wjl (Wolfgang Lonien) said...

I can second that, ALoK. We have several of those in the house, and the AWB sets the camera to about 2600K, according to RawTherapee - which would translate to about 2650K if you'd set it manually on my camera.

Impossible to properly filter my flash to exactly that temperature with the Roscoe set, at least for me. And if I use a full and a half CTO, I also lose lots of power from that little GN 38 (in m) flash...

October 08, 2010 12:05 AM  
Blogger PShizzy said...


You can double up filters, adding a CTB filter, perhaps a 1/4 or 1/8th, to bring the temp up a little more, but if you encounter off type lighting that doesn't work with a simple CTO, CTB or Minus/Plus Green, then try shooting a white balance card with a daylight white balance preset. This will show you the cast you have. At that point, you can figure out how best to neutralize the cast. You can take another test shot after gelling your lights and see what the cast looks like to get an idea of how close you are. If your camera has liveview, you can even zoom into the card and use a live histogram to see the effects in realtime.


October 08, 2010 12:20 AM  
OpenID tomaszbrodecki said...

I thought I can trust that at least Rosco people would know that there's no such thing as "degree Kelvin" o_O

October 08, 2010 5:01 AM  
Blogger Jim said...

...and then the hippies took over and we have CFL... That made me laugh louder than anything I've read this morning. As a non hippie, I make a considerable effort to install CFL's in my house with a color temp near 5000K. They're out there if you look.

October 08, 2010 12:06 PM  
OpenID damnuglyphotography said... lemme get this straight......if I wanna mix strobe and fluorescents and correct the fluorescents in a shot like this...

Lotsa Fluorescents!!!

....I would hafta bring 3 or 4 - 25 foot rolls of Rosco's FlouroFilter....yeah...that's not gonna happen! That's why the Good Lord invented Photoshop...and why I don't care about "real" color!

October 08, 2010 12:10 PM  
Blogger Steve Salt said...

I often shoot in corporate environments and have noticed more and more CFLs installed are getting really close to daylight. My greens have stayed in the bag for months now and i often shoot bare flash with minimal tweak in HSL. Although i'm thinking of getting 1/4 or 1/8 green.

October 08, 2010 12:45 PM  
Blogger cabbiinc said...

damnuglyphotography, this video is aimed at the cinema industry where gelling existing light sources is just doing what's gotta be done. It's just part of the job. But for us run and gun photogs (anyone that doesn't spend 4 times longer setting up lighting than shooting) then it would make more sense to gel YOUR FLASH to match ambient temps than the existing lights.

October 08, 2010 2:05 PM  
Blogger Larry Vaughn said...

I got a case of the cfl's that come in the blue package this is supposed to be daylight. Has anyone tested these for accurate color?

Easy to change a few bulbs out, harder to do the whole office. I'm also thinking video here....

October 08, 2010 3:02 PM  
Blogger Larry Vaughn said...

I change the cfl's if there are just a few, for video use.

Has anyone tested the Home Depot daylight bulbs (blue package) for color shifts?

October 08, 2010 3:03 PM  
Blogger Alonzo Riley said...

"an ordinary person much like yourself"

OMG I can't stop laughing. That really made watching the video near impossible! It's the joke that keeps coming and coming!

October 08, 2010 4:09 PM  
Blogger Paul said...

I often shoot in factories lit with a wide range of light sources, no two of which are alike. I contacted Rosco a couple of years ago, suggesting that the company strike a deal with Seconik to develop a color meter that would provide users with Rosco gel numbers for correction. It seemed like a great idea to me. The Rosco folks said color metering was too imprecise of a science for such a device. That's too bad. I'm sure the company could sell about 1.258 million of them.

October 08, 2010 4:30 PM  
Blogger Daniel & Alesia Jester said...

Thanks so much for this post on CFL's I have so much trouble just shooting at home with those things

October 08, 2010 5:38 PM  
OpenID paultklein said...

can't you just do a custom white balance?

October 08, 2010 5:49 PM  
Blogger James Cooke said...

I only use CFLs at home for dim side lights in the evening.

I have replaced the main CFLs with halogen 60W. Halogen offers some energy savings vs. regular bulbs, and the colour is pure. Also full power straight away, I mean light like the old 100W of old, now banned in Europe. Also slightly cooler than florescent, so better for non-gelled flash.

If you read up on CFLs it seems (I'm not an expert) that most are not capable of high colour variation so no amount of filters will solve the problem I think, at least not when you have a choice in your own home. CFLs give me a headache.

October 08, 2010 7:19 PM  
Blogger Boris said...

As Steve Salt said "I often shoot in corporate environments and have noticed more and more CFLs installed are getting really close to daylight."
Here in Europe CFL producers are labeling the lights as 830/840 or 950. What that means - 8 or 9 in the first place means the spectrum uniformity (9 is max, so very very close to uniform), with 8 they have a bit of boosted greens and less reds. The second two nubers are for kelvin: 30-3000k 40-4000k. So 950, that i have installed in studio are very close to daylight, a little bit warmer than my elinchrom's (5300), but nothing to worry about.
But it's true - 830/840 are a bit cheaper than 950...

October 09, 2010 5:23 PM  
Blogger Wink of an eye Digital said...

Carful on the Hippie thing we also bring you LED' that's when gang use of these things are going to be a game changer in photo and video work.

Peace dude

October 09, 2010 7:01 PM  
Blogger Public said...

Ok, sustainable fluorescent light-bulb... but is it really proper green?

If you're really committed on sustainability, then you should consider making a difference in your own home... this way you're bill will come down to half!! Think about it.


October 14, 2010 6:43 AM  
Blogger David said...

Actually, it is a reduction of approximately 77% over incandescents. We switched long ago, before going full PV and hot water solar, too.

DH <-(Gets it.)

October 14, 2010 7:26 PM  
Blogger Sandy said...

I have worked for over 25 years as a chief lighting technician (gaffer) in the motion picture industry and am just now taking my sorry, tired ass off set and starting my own photo biz. I've enjoyed making the switch from hot lights to flash and now feel I can do more with less. One thing that bugs me about photo gear is the flimsiness of the gear, that just drives me nuts. Anyway from a gaffers point of view when dealing with florescents I would not gel the tubes or the fixtures. It's far easier and cheaper to go to a lighting rental company and get Durotest 3200 tubes or Chroma 50's at 5000 for a buck apiece rather than spend $180 a roll for gel. Alternatively you can rent Kinoflow fixtures with cool whites, warm whites or what ever in them. I find that gelling lamps is more time consuming and expensive than changing fixtures.

October 27, 2010 8:06 PM  

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