Colour balance mistake

Alex Wren · June 3rd, 2006, 01:24 PM

Hi Forum,

Recently I have shot some interviews for a short video clip. In my haste (and inexpertise!) I think I forgot to put the white balance onto the correct setting.

I have attached a screen shot of the problem clip.

Using Premiere Pro 1.5 I would love to know how to put this right. I have never done any colour corrction before and in my attempts all I can seem to do is make it look worse.

If any kind soul out there could offer me a noddy guide on how to make this look better then I would be enternally greatful.

Thanks in advance...

Graham Bernard · June 3rd, 2006, 04:52 PM

Is this any better?

I don't use Prem - SONY Vegas here. But I did do this quickly in PaintShop just to get your feedback.

If you wish to take this further please email me - yeah? I'm based in London . . .so!

Regards,

Grazie

Tim Bickford · June 3rd, 2006, 06:41 PM

High-

I took a crack at this with P-Pro 2.0.

Your original has too many reds + no mids. This is what I did.

1) Using the vectorscope as a guide, I used the master hue offest to shift the reds into the "safe zone"

2) Using the luma corector (P-pro 2) I just lowered the master gamma + lowered the contrast a bit.

3) Finally, I used the RGB curves - using the master, I stretched the blacks a bit.

You lose a bit of detail - but get some decent color back. It's a bit easier on the eyes too.

Tim

Glenn Chan · June 3rd, 2006, 11:08 PM

I took a crack at it with photoshop... you can do the same thing in After Effects, but not necessarily Premiere Pro.

What I did was just replace the color in the man's face with flesh tone color. The way to do this in AE would be to key the man's flesh tone out. Then on an upper layer, make it flesh tone color and set the composite mode to "color".
(Sorry, this is a really really brief description. Ask for details. I also glossed over some things like using levels to set a basic white balance.)

2- I'm not sure, but part of the problem may be that the image is slightly overexposed.

3- If you look at the shadow, it's purple/magenta comapred to the wall around it. It seems to indicate that the subject was lit with mixed color temperatures (the light is different colors). Yellow/magenta is usually a combination to avoid.

4- If you feel like it, you can isolate the magenta color and use it to adjust the lighting on the man's face. Use the hue/saturation filter, select magentas, expand out the selection/isolate, and drop the lightness setting. The image on the right shows the result. Incidentally, the magenta cast is not very visible anymore.

I have no idea why that works... it might be a combination of how the HSL color space works and how human vision works. That shadow is definitely red/magenta, but doesn't appear so.

Alex Wren · June 4th, 2006, 02:39 AM

Thanks everyone,

A whole collection of things to try!

Just to explain the shot in a bit more detail, I used tungsten all round (in a dark room) but used a light purple filter on the back wall hence the red/purple. This was actually done on purpose but maybe I am regretting it now.

I will have a bash at sorting this out now. I was intending to use Premiere Pro 1.5 although if anybody knows of some other applications worth considering please let me know.

It seems like I might need to buy a book and do some serious research in the future to stop this happening again (book suggestions would be greatfully received).

Thanks again - I will post up some of my attempts.

Alex

Alex Wren · June 4th, 2006, 02:42 AM

Quote:

Originally Posted by Graham Bernard

Is this any better?

I don't use Prem - SONY Vegas here. But I did do this quickly in PaintShop just to get your feedback.

If you wish to take this further please email me - yeah? I'm based in London . . .so!

Regards,

Grazie

Thanks Graham,

That does look better although as I am using a laptop (Dell Inspiron 510m) I am not convinced the screen helps me see it properly anyway..

Alex Wren · June 4th, 2006, 02:46 AM

Quote:

Originally Posted by Glenn Chan

What I did was just replace the color in the man's face with flesh tone color. The way to do this in AE would be to key the man's flesh tone out. Then on an upper layer, make it flesh tone color and set the composite mode to "color".
(Sorry, this is a really really brief description. Ask for details. I also glossed over some things like using levels to set a basic white balance.)

Cheers Glenn,

I do have After Effects although to be honest I have not used it (still getting to grips with Premiere). Is it worth having a go or do you think I will get myself in a twist with new software that I am not familiar with?

If it is easy enough I will have a go - I think someone told me it is a nightmare to learn so I have avoided it!

Alex

Glenn Chan · June 4th, 2006, 02:09 PM

Lighting and camera information:

Lighting books:
?Lighting for Television and Digital Video? - John Jackman This book is very practical.
Matters of Light and Depth - Ross Lowel

In your case, it may have made more sense to cast an interesting pattern on the wall, not just a wash of purple. You could use the barn doors and sort of make a slash of light, or use a piece of material with a pattern cut into it, or use two different kinds of gels on the light so there's a gradient between two colors, etc.

Camera:
If you use a field monitor, you'll know right away what the image looks like.
*Don't use consumer monitors, they can make underexposure look ok.

If you don't have a monitor, then you have to learn how to use the zebras on your camera. Do tests and learn how the zebras correlate to exposure.
Perhaps do a test like the following:
http://www.glennchan.info/video/exposure/exposure.htm
Your camera may have both 70% and 100% zebras (or some other %). 100% corresponds to maximum legal white (some cameras record information above 100%). Anything above 100% will usually be clipped, unless you can treat the footage in post.

The simple story is that anything over 100% will get clipped... so anything that is zebra'ing (with 100% zebras) won't have any visible detail in it.
One thing to usually do is to make sure a specular reflection has zebras on it.

If you have 70% zebras on, you usually want some of the face to have zebra stripes on it.

There really is no right exposure... the ideal exposure is an aesthetic decision. Do a test and figure out what you like.

------------------------------
After Effects has a high learning curve if you want to do very good broadcast design work with it. Most people use After Effects for that, and to do good work you really need to know most of the features.

The program itself is not ridiculously complicated. If you have After Effects, why not start learning it?

Tim Bickford · June 4th, 2006, 08:27 PM

I thought I'd throw in my two cents on a field monitor.

Find an old Commodore 1702 video (NTSC) monitor (typically $30 to $50 used) and make a S-Video cable (Radio Shack) $20 with S-video on one end and two RCA (luma and chroma) on the other. These old monitors are good in the field + can take a beating too. You can also calibrate to color bars.

Tim

June 3rd, 2006, 01:24 PM	#1
Alex Wren Regular Crew Join Date: Nov 2004 Location: UK Posts: 161	Colour balance mistake - see screenshot... Hi Forum, Recently I have shot some interviews for a short video clip. In my haste (and inexpertise!) I think I forgot to put the white balance onto the correct setting. I have attached a screen shot of the problem clip. Using Premiere Pro 1.5 I would love to know how to put this right. I have never done any colour corrction before and in my attempts all I can seem to do is make it look worse. If any kind soul out there could offer me a noddy guide on how to make this look better then I would be enternally greatful. Thanks in advance... Attached Thumbnails

June 3rd, 2006, 04:52 PM	#2
Graham Bernard Old Boot Join Date: Aug 2002 Location: London UK Posts: 3,633	Is this any better? I don't use Prem - SONY Vegas here. But I did do this quickly in PaintShop just to get your feedback. If you wish to take this further please email me - yeah? I'm based in London . . .so! Regards, Grazie Attached Thumbnails

June 3rd, 2006, 11:08 PM	#4
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	I took a crack at it with photoshop... you can do the same thing in After Effects, but not necessarily Premiere Pro. What I did was just replace the color in the man's face with flesh tone color. The way to do this in AE would be to key the man's flesh tone out. Then on an upper layer, make it flesh tone color and set the composite mode to "color". (Sorry, this is a really really brief description. Ask for details. I also glossed over some things like using levels to set a basic white balance.) 2- I'm not sure, but part of the problem may be that the image is slightly overexposed. 3- If you look at the shadow, it's purple/magenta comapred to the wall around it. It seems to indicate that the subject was lit with mixed color temperatures (the light is different colors). Yellow/magenta is usually a combination to avoid. 4- If you feel like it, you can isolate the magenta color and use it to adjust the lighting on the man's face. Use the hue/saturation filter, select magentas, expand out the selection/isolate, and drop the lightness setting. The image on the right shows the result. Incidentally, the magenta cast is not very visible anymore. I have no idea why that works... it might be a combination of how the HSL color space works and how human vision works. That shadow is definitely red/magenta, but doesn't appear so. Attached Images

June 4th, 2006, 08:27 PM	#9
Tim Bickford Major Player Join Date: Sep 2005 Location: New Hampshire Posts: 448	I thought I'd throw in my two cents on a field monitor. Find an old Commodore 1702 video (NTSC) monitor (typically $30 to $50 used) and make a S-Video cable (Radio Shack) $20 with S-video on one end and two RCA (luma and chroma) on the other. These old monitors are good in the field + can take a beating too. You can also calibrate to color bars. Tim Last edited by Tim Bickford; June 5th, 2006 at 05:19 AM.

June 4th, 2006, 02:39 AM	#5
Alex Wren Regular Crew Join Date: Nov 2004 Location: UK Posts: 161	Thanks everyone, A whole collection of things to try! Just to explain the shot in a bit more detail, I used tungsten all round (in a dark room) but used a light purple filter on the back wall hence the red/purple. This was actually done on purpose but maybe I am regretting it now. I will have a bash at sorting this out now. I was intending to use Premiere Pro 1.5 although if anybody knows of some other applications worth considering please let me know. It seems like I might need to buy a book and do some serious research in the future to stop this happening again (book suggestions would be greatfully received). Thanks again - I will post up some of my attempts. Alex

June 4th, 2006, 02:09 PM	#8
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	Lighting and camera information: Lighting books: ?Lighting for Television and Digital Video? - John Jackman This book is very practical. Matters of Light and Depth - Ross Lowel In your case, it may have made more sense to cast an interesting pattern on the wall, not just a wash of purple. You could use the barn doors and sort of make a slash of light, or use a piece of material with a pattern cut into it, or use two different kinds of gels on the light so there's a gradient between two colors, etc. Camera: If you use a field monitor, you'll know right away what the image looks like. *Don't use consumer monitors, they can make underexposure look ok. If you don't have a monitor, then you have to learn how to use the zebras on your camera. Do tests and learn how the zebras correlate to exposure. Perhaps do a test like the following: http://www.glennchan.info/video/exposure/exposure.htm Your camera may have both 70% and 100% zebras (or some other %). 100% corresponds to maximum legal white (some cameras record information above 100%). Anything above 100% will usually be clipped, unless you can treat the footage in post. The simple story is that anything over 100% will get clipped... so anything that is zebra'ing (with 100% zebras) won't have any visible detail in it. One thing to usually do is to make sure a specular reflection has zebras on it. If you have 70% zebras on, you usually want some of the face to have zebra stripes on it. There really is no right exposure... the ideal exposure is an aesthetic decision. Do a test and figure out what you like. ------------------------------ After Effects has a high learning curve if you want to do very good broadcast design work with it. Most people use After Effects for that, and to do good work you really need to know most of the features. The program itself is not ridiculously complicated. If you have After Effects, why not start learning it?