Fluorescent vs skin tone at DVinfo.net

Donald Blake · January 25th, 2009, 02:16 PM

Hi everyone,

I built a home made lighting kit (see JPGs) I used 3 basic lighting fixtures, they each have 2 48" T8 fluorescent tubes. Basically they're sold to be used in garages (I know I'm not the first one to do this) I have 6-6500K tubes for cold type lighting and 6-3200K tubes for wharm also.

So here's the situation;
From rescent tests I made the cold lighting makes the skin look yellowish, I want to have that regular pink skin look, even in post production with the color correction I'm having a hard time getting it. With the warm lighting tubes the skin turns out ok yet you can still notice a bit of yellow in there.

I have a camera F-DL filter which I tought would fix my problem but it dosent seem to change much, I tested the warm and cold White balance on my camera and can't seem to find the right settings or combination of all this.

Thanks in advance!

Perrone Ford · January 25th, 2009, 02:24 PM

Does your camera have a white balance button? Do you have a white card or a white sheet of paper? If yes to these, you should be able to do what you need.

Seth Bloombaum · January 25th, 2009, 04:48 PM

Perrone's post refers to one of the potential problems - a mismatch between the color temp of your cam and the tubes.

Another potential problem, maybe your tubes aren't sufficiently full-spectrum. Exciting the gasses in an flo tube to glow isn't enough to provide good color, the manufacturer also coats the inside of the tube with phosphors that glow (edit: the right phosphors will even out the color rendition). A tube that is good for video will have a relatively high CRI (color rendition index), meaning relatively more full-spectrum light than something sold for the garage.

Most tubes are now a lot better than the days in which most fluorescent lighting was truely heinous even to the eye, but of course the camera is a lot more discriminating.

So, if you're still unhappy with color rendition after the custom white balance that Peronne recommended, you may be shopping for new tubes. Sometimes hard to find the actual CRI info, sometimes easy, but you're probably looking for 85 or better.

Cool-looking fixtures, btw :-)

Steve Rusk · January 25th, 2009, 08:50 PM

To add to what Seth already pointed out, the best CRI rating I've seen outside dedicated Kino Flo bulbs was called Sunstick (or something like that) from Lowe's. It had a CRI of 90 and a color temperature of 5000K. They had been $20 for a box of 10, but last time I saw them, the price had jumped to $29. Still a bargain for good lighting.

Donald Blake · January 26th, 2009, 11:10 AM

Ok I managed to get the CRI info and it's at 78.

Take a look at my JPG (taken from post-production) and here's all my setings, tell me if you see something wrong ;

LIGHTING :
6 - T8 48" 6500K 78CRI tubes, horizontal with reflectors right next to the camera (60" from subject)
2 - T8 48" 6500K 78CRI tubes, vertical on the back side of the subject.

CAMERA (HDR-FX1) :
0 gain
F3.1 Iris
60 Shutter Speed
White balance set with a white piece of paper at the subjects exact location

POST-PRODUCTION (vegas) :
+0,15 contrast added
+1,20 saturation added
+0,05 red added (midtones, color balance)
+noise reduction (smart smoother)

Ok forget about the background, would this be acceptable for a information video where the subject talks about a product or a company? thanks in advance!

Perrone Ford · January 26th, 2009, 11:27 AM

It's hard to judge the colors because half the frame is clipped.

CRI of 78 is a bit dicey to me. I'd feel a bit uncomfortable working below 85.

Donald Blake · January 26th, 2009, 12:04 PM

Sorry Perrone I should've specifyed that the JPG you saw was just a test and the final product will be in front of a green screen, So never mind the surrounding color what I'm looking for is the Skintone color.

I tought the skintone was a little pale, so I did another one and added saturation (1,30) and took out brightness (-0,10) see my new JPG

For the CRI issue, I'll be on the look out for higher CRI tubes, but for the moment that's what I have.

Perrone Ford · January 26th, 2009, 12:29 PM

Can you drop an unprocessed frame grab on my FTP server? The link is in my profile. Just drop it at the root. But don't do a jpg. Do a PNG, or Targa (TGA), or a TIFF if that's all you can do. These JPGs are just to blocky for me to make any reasonable comment about the skin tone.

Donald Blake · January 26th, 2009, 02:23 PM

Done .

Doug Bennett · January 26th, 2009, 02:50 PM

the image has a blue/green cast - I would guess partly due to low CRI and partly incorrect white balance.

You cannot accurately determine WB for a 3 dimensional object by measuring the reflection from a piece of card - use a monitor or plug the cam into a laptop and use the scopes in the NLE.

Perrone Ford · January 26th, 2009, 03:01 PM

Mailed you back after making a few corrections.

-P

Donald Blake · January 26th, 2009, 03:39 PM

Ok thanks Perrone, I'm looking at your PNG and it looks more lifelike than mine, can you explain what effect did you add to it or send the VEG files in your reply?

Donald Blake · January 26th, 2009, 03:44 PM

Doug, is that what you do everytime you film something? you always have a laptop plugged to your camera? and what program are you using (NLE)?

Dave Dodds · January 26th, 2009, 03:47 PM

So the only problem is that you think she's a bit pale? Is she pale in real life? Perhaps all you need is a little warmth, like an 1/8 cto or even a cosmetic pink on the flo (WB first without the gel).

From a quick look on a regular computer monitor, I don't really see a problem with her skin tone. It looks pale, sure, but not unnatural. If the paleness is the only problem, all you really need is what I mentioned above.
Good luck.

~~Dave

Donald Blake · January 26th, 2009, 04:05 PM

Quote:

Originally Posted by Dave Dodds

So the only problem is that you think she's a bit pale? Is she pale in real life?

Actually the original problem (if you read the very first post) was yellow skintone with the fluorescent lighting.

And she's actually tanned in real life.

I'm having a hard time finding the right settings or should I say the right mix (lighting/camera/post-prod), I'm doing a lot of testing and I can't seem to get that winning combination. Ok I don't have the yellow skintone anymore but I don't have her real skintone either.

Can overlighting the subject ruin everything in post-production? my Iris was open at 3.1 maybe I should've closed it a bit more?

January 25th, 2009, 02:16 PM	#1
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Fluorescent vs skin tone Hi everyone, I built a home made lighting kit (see JPGs) I used 3 basic lighting fixtures, they each have 2 48" T8 fluorescent tubes. Basically they're sold to be used in garages (I know I'm not the first one to do this) I have 6-6500K tubes for cold type lighting and 6-3200K tubes for wharm also. So here's the situation; From rescent tests I made the cold lighting makes the skin look yellowish, I want to have that regular pink skin look, even in post production with the color correction I'm having a hard time getting it. With the warm lighting tubes the skin turns out ok yet you can still notice a bit of yellow in there. I have a camera F-DL filter which I tought would fix my problem but it dosent seem to change much, I tested the warm and cold White balance on my camera and can't seem to find the right settings or combination of all this. Thanks in advance! Attached Thumbnails

January 25th, 2009, 02:24 PM	#2
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Does your camera have a white balance button? Do you have a white card or a white sheet of paper? If yes to these, you should be able to do what you need. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

January 25th, 2009, 04:48 PM	#3
Seth Bloombaum Inner Circle Join Date: Sep 2003 Location: Portland, Oregon Posts: 3,420	Perrone's post refers to one of the potential problems - a mismatch between the color temp of your cam and the tubes. Another potential problem, maybe your tubes aren't sufficiently full-spectrum. Exciting the gasses in an flo tube to glow isn't enough to provide good color, the manufacturer also coats the inside of the tube with phosphors that glow (edit: the right phosphors will even out the color rendition). A tube that is good for video will have a relatively high CRI (color rendition index), meaning relatively more full-spectrum light than something sold for the garage. Most tubes are now a lot better than the days in which most fluorescent lighting was truely heinous even to the eye, but of course the camera is a lot more discriminating. So, if you're still unhappy with color rendition after the custom white balance that Peronne recommended, you may be shopping for new tubes. Sometimes hard to find the actual CRI info, sometimes easy, but you're probably looking for 85 or better. Cool-looking fixtures, btw :-) Last edited by Seth Bloombaum; January 25th, 2009 at 07:52 PM. Reason: clarification of phosphors info

January 26th, 2009, 11:10 AM	#5
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Ok I managed to get the CRI info and it's at 78. Take a look at my JPG (taken from post-production) and here's all my setings, tell me if you see something wrong ; LIGHTING : 6 - T8 48" 6500K 78CRI tubes, horizontal with reflectors right next to the camera (60" from subject) 2 - T8 48" 6500K 78CRI tubes, vertical on the back side of the subject. CAMERA (HDR-FX1) : 0 gain F3.1 Iris 60 Shutter Speed White balance set with a white piece of paper at the subjects exact location POST-PRODUCTION (vegas) : +0,15 contrast added +1,20 saturation added +0,05 red added (midtones, color balance) +noise reduction (smart smoother) Ok forget about the background, would this be acceptable for a information video where the subject talks about a product or a company? thanks in advance! Attached Thumbnails

January 26th, 2009, 11:27 AM	#6
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	It's hard to judge the colors because half the frame is clipped. CRI of 78 is a bit dicey to me. I'd feel a bit uncomfortable working below 85. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

January 25th, 2009, 08:50 PM	#4
Steve Rusk Regular Crew Join Date: Jan 2009 Location: Stuttgart Germany Posts: 63	To add to what Seth already pointed out, the best CRI rating I've seen outside dedicated Kino Flo bulbs was called Sunstick (or something like that) from Lowe's. It had a CRI of 90 and a color temperature of 5000K. They had been $20 for a box of 10, but last time I saw them, the price had jumped to $29. Still a bargain for good lighting.

January 26th, 2009, 12:04 PM	#7
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Sorry Perrone I should've specifyed that the JPG you saw was just a test and the final product will be in front of a green screen, So never mind the surrounding color what I'm looking for is the Skintone color. I tought the skintone was a little pale, so I did another one and added saturation (1,30) and took out brightness (-0,10) see my new JPG For the CRI issue, I'll be on the look out for higher CRI tubes, but for the moment that's what I have. Attached Thumbnails

January 26th, 2009, 12:29 PM	#8
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Can you drop an unprocessed frame grab on my FTP server? The link is in my profile. Just drop it at the root. But don't do a jpg. Do a PNG, or Targa (TGA), or a TIFF if that's all you can do. These JPGs are just to blocky for me to make any reasonable comment about the skin tone. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

January 26th, 2009, 02:23 PM	#9
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Done .

January 26th, 2009, 02:50 PM	#10
Doug Bennett Major Player Join Date: Oct 2004 Location: NYC Posts: 260	the image has a blue/green cast - I would guess partly due to low CRI and partly incorrect white balance. You cannot accurately determine WB for a 3 dimensional object by measuring the reflection from a piece of card - use a monitor or plug the cam into a laptop and use the scopes in the NLE.

January 26th, 2009, 03:01 PM	#11
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	Mailed you back after making a few corrections. -P __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

January 26th, 2009, 03:39 PM	#12
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Ok thanks Perrone, I'm looking at your PNG and it looks more lifelike than mine, can you explain what effect did you add to it or send the VEG files in your reply?

January 26th, 2009, 03:44 PM	#13
Donald Blake Regular Crew Join Date: Dec 2006 Location: Montreal, Canada Posts: 142	Doug, is that what you do everytime you film something? you always have a laptop plugged to your camera? and what program are you using (NLE)?

January 26th, 2009, 03:47 PM	#14
Dave Dodds Major Player Join Date: Apr 2006 Location: New York Posts: 204	So the only problem is that you think she's a bit pale? Is she pale in real life? Perhaps all you need is a little warmth, like an 1/8 cto or even a cosmetic pink on the flo (WB first without the gel). From a quick look on a regular computer monitor, I don't really see a problem with her skin tone. It looks pale, sure, but not unnatural. If the paleness is the only problem, all you really need is what I mentioned above. Good luck. ~~Dave