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Old May 17th, 2006, 02:45 AM   #1
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When to White Balance?

This is another question of mine that is long overdue.

Let us assume that you are going to shoot a live concert that has different coloured lighting and effects. This would also apply to shooting a music video, for example, with footage of the band playing with different coloured lighting i.e. colors changing all the time.

How or when would you (or should you) adjust the white balance of your cameras (I am using a combinations of Sony FX1's and Sony VX2100's)?

What I mean to ask is - if it is possible (before the shoot) should you manually adjust the white balance with white light on the subject (band on stage) i.e. as the subject would appear in white light and then the colors would be correct after that - or what???

Regards,

Dale.
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Old May 17th, 2006, 06:36 AM   #2
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I would definitely white balance once and leave it alone. Otherwise, the camera will try to compensate for the colored filters by making them more white/colorless. Since stage lights are usually tungsten, you could probably set your camera manually to 3200K and have a decent result. The unfiltered lights would look white and the gels would have the appropriate color intensity. It might be hard to white-balance manually with something white on the stage unless you have completely free access.
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Old May 17th, 2006, 12:52 PM   #3
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Dale,

You have it partly right. Yes, you want to manually white balance while only unfiltered, white lights are on. However, you do not want to manually white balance with the band on stage. That's not how manual white balance is intended to work. You need a white or gray reference card filling your frame, with the light shining on it, then you hit the white balance.

Since that situation may never happen, it's best to just set the balance to tungsten and leave it. If it's little off, you can make one big color correction pass on all the footage in post.

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Old May 17th, 2006, 04:14 PM   #4
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White balance all the camera at the same time under the same light (3200k) or stage work lights, on the same card... You may have to adjust in post due to the colorimetry differances in each camera, but at least they should be in the same ballpark, although possibly in the right and left bleachers.
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Old May 19th, 2006, 04:18 AM   #5
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Hi everyone - and thanks for the responses.

Sorry - I should have been more specific.

I would use white balance cards so the question should probably have been:

Using white balance cards - when should I white balance - under white or coloured lights.

All of the responses say to set the camera manually to 3200k.

How would I do this with Sony FX1's and Sony VX2100's? Does anyone know what the presets default to i.e. 'Outdoor' and 'Indoor' presets.

Regards,

Dale.
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Old May 19th, 2006, 11:36 AM   #6
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Quote:
Originally Posted by Dale Paterson
Using white balance cards - when should I white balance - under white or coloured lights.
Under white light. This is assuming that you want the color rendition of skin tones to be correct when the band is lit by white light.

In many cases, your camera won't even be able to white balance with a color source, giving the message "out of range" or some indecipherable icon.

When the club turns on the colored lights the camera will be *much* more sensitive to this than your eye.

Quote:
Originally Posted by Dale Paterson
All of the responses say to set the camera manually to 3200k.
How would I do this with Sony FX1's and Sony VX2100's? Does anyone know what the presets default to i.e. 'Outdoor' and 'Indoor' presets.
You'll want the "indoor" preset. This will be 3200 or close to it.

In summary: White balance with white light if possible. If not, use the indoor preset.
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Old May 20th, 2006, 07:26 PM   #7
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I disagree, to a certain extent.

Decide ahead of time what you want the finished video to look like. Do you want to neutralize the colors of the lighting, or do you want to do your best to create what the audience saw live?

Then you need to look at what lighting effects will be used. What range of colors will be hitting the performers, what angles, etc. Are there going to be times when the performers will be mostly in silhouette, and there is barely enough light on the performers' faces to render them sufficiently for the live audience to see them? The camera definitely won't capture such extreme looks. I think it is more important to capture the colors of the light onstage, and don't stress out about not seeing their faces during such sequences.

When I do this kind of video work, I am almost always interested in recreating the lighting as experienced by the live audience. That means you need to push things a little bit. I want those blues to read. If the show is dominated mostly by warmer colors, then by all means, do a neutral white balance. The colors will come through fine.

I always do a manual white balance. I almost always ask the lighting people to show me what colors are being used beforehand, then ask them to set up a cue onstage that is a bit warmer (closer to red) than what worklights, or a truly neutral color will provide. The camera is a lot more sensitive to warm colors than cool ones, so if you set your balance a little warm, the cooler colors will have more 'pop' to them. There will be plenty of 'pop' to the reds, oranges and yellows even if you set your white balance right in the middle of them. By taking a more neutral white balance, you tend to wash out the cool colors. Blues in the final product will be a lot closer to white, and the whole thing will be a little less exciting, in my reckoning.

Theatrical lighting is a challenge to capture correctly, no doubt about it. If you can experience a performance before you need to shoot it, you will get a lot closer to what you need to do to when you are holding a camera. Keep in mind that the camera's color sensitivity is a lot different than your own.

Definitely white balance all the cameras under the same light, and be very careful about the impact of angled light on that card, for cameras that are at different orientations to the stage. You will get very different looks if you aren't careful.

Seth's comment "assuming that you want the color rendition of skin tones to be correct when the band is lit by white light" is often not practical. Not many bands are going to have a "white light" source in their lighting, and it won't likely be used during the performance.

Don't be afraid of the colors that they are using. You need to make it work for you, rather than merely try to neutralize it.
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Old May 20th, 2006, 09:22 PM   #8
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Quote:
Originally Posted by Brian Miller
I disagree, to a certain extent.

Decide ahead of time what you want the finished video to look like...

When I do this kind of video work, I am almost always interested in recreating the lighting as experienced by the live audience...

Theatrical lighting is a challenge to capture correctly, no doubt about it. If you can experience a performance before you need to shoot it, you will get a lot closer to what you need to do to when you are holding a camera. Keep in mind that the camera's color sensitivity is a lot different than your own...

Seth's comment "assuming that you want the color rendition of skin tones to be correct when the band is lit by white light" is often not practical...
Brian makes some good points, reflective of an approach pretty different than mine. Dale, you'll have to decide what works best for you (and your client?).

Quote:
Not many bands are going to have a "white light" source in their lighting, and it won't likely be used during the performance.
My experience has been different. Most lighting designs I've worked with have a white circuit, a blue circuit, and a red circuit on the fronts and side booms, plus some spot instruments of various colors, and a followspot.

I say find a standard in white light, then treat for color in post. To be honest, I've not tried to do what Brian prefers. It sounds like he's shot under theatrical light enough to predict how color will look through the process. I have too - when the light is white I want skin tones to be right. Different color looks can always be added in post.

However, the basic challenge remains, and I think Brian and I are agreeing on it. Theatrical colors just don't present to the camera the way they present to the eye. Brian and I have described two different approaches, but there is a third approach that is better if it can be produced:

Light it for video. Two ways to use color, for back and side boom efx, and for front efx. For back and siders you can usually use theatrical gel, get that nice color rim, present red from the side, etc.

IMO, for the front lights, you'd test the lighting director's existing sets and have him or her paint for video. In most cases this means adding color to the white light, rather than replacing with color. The best thing to do is get a good monitor in front of the L.D. and have them paint to that. If you have this level of flexibility you might walk away with a product all the better for the L.D.'s creative ideas as well as your own. If they are willing to re-gel, it'd be light straw or amber instead of yellow, rose instead of red, etc.

One thing I want to avoid is getting the supersaturated colors that crawl and spill off the subjects. That isn't what the L.D. intended and isn't what the live audience saw, but is all too easy with theatrical light for video. YMMV.
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Old May 21st, 2006, 02:22 AM   #9
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Good Morning, and thank you very much for the detailed responses.

My problem really is just getting my head around the concept - I think I'd be OK after the penny drops.

My understanding is that by manually adjusting the white balance what you are actually saying to the camera is 'under these lighting conditions - this is what white looks like'. Correct?

Where my confusion comes in is that under white light - white appears as 'X' let's say - but under blue light - white appears as 'Y' (or does it)? My brain doesn't quite get this - white is white!!!

Let's say that I am looking at a stage (or any scenario where the light will change color). My logic is telling me that I should be able to take a white balance card (or a warmcard which I have just purchased) - point the camera at the card under white light - manually adjust the white balance - and any changes in the light color after that should be correct i.e. under white light - white is then white - but if the light changes to blue for example - then even to our eyes the white will look blue. Am I getting this?

I have just ordered some PAR 64's which I should get next week. I think I must buy some colored gels and test. I also bought a 6 channel dimmer.

Which prompts another question:

The PAR 64's were ordered with 1000W tungsten lamps. Would I be correct in saying this - in a smaller space i.e. if the 1000W lamps were too overpowering - is it not better to use 500W lamps (for example) at full power - than to dim 1000W lamps. The reason that I ask is that in the shop I noticed that when the 1000W lamps were dimmed (or any of the other lights on display for that matter) the light becomes noticeably yellow. Is manual white balance able to compensate for this?

By the way - as Brian phrased it - I want to do my best to create what the audience saw live. I love editing but I simply hate altering things like color, brightness, etc. etc. I'm always scared of going too far with these type of corrections and making things look unnatural. I tend to work on the premise of 'that is what the scene looked like when I shot it - if it was dark - it was dark - that's the way it was'. I doubt that would get me very far in Hollywood but so be it.

Regards,

Dale.
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Old May 21st, 2006, 07:50 AM   #10
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I shoot a lot of performances, and my experience is that you just cannot get your video to really look the same as what the audience sees, no matter what you do! A lot of good things have been written here already, and I don't have much to add. Personally, I don't bother to do custom white balance anymore. I just set the camera for incandescent (the little light bulb icon appears on the screen) and then I tweak as needed in post.

But camera sensors don't respond the same as eyeballs, so you just won't ever get correct results in every situation. And realize that the whole way a camera perceives color is not really accurate in the first place. For example, you can use a blue gel or filter to "correct" incandescent light and make it look like daylight to the camera. But in reality, daylight is the full spectrum which contains all colors, and tungsten light is only a small yellowish subset of colors. Adding gels and filters is a form of subtractive mixing - it takes colors away from the light. So adding a gel to artificial light is really removing some of the warm colors and not making it white. The camera will perceive it that way, but your eyes won't.

Since you're using an FX1 there's a handy little trick I use often on my Z1 which you might enjoy experimenting with. Set your white balance for outdoors and go into the assign button menu. You can assign two of the buttons to shift white balance up and down and this lets you easily see the effect of tweaking the color temperature. IIRC, punching these buttons will bump your white balance up and down in 500K increments. I don't use this for performances (since I just use the indoor preset), but I use it quite a bit for everything else. I find it especially handy in a mixed lighting situation where you have some flourescents/tungsten/outdoor light and need to find a compromise. This function is only available in outdoor mode for some reason, but it's really handy since the assign buttons give you quick access; give it a try.

And yes, it is a big problem the way color temperature changes as you dim lights so you should try to match the wattage of your instruments to the levels you need. In theatrical lighting we often use pale blue gels to help somewhat with this situation, but I don't think there really is a solution. Even with a light blue gel, a stagelight will read as amber if you run it at 50%.

I've been doing theatrical lighting for over 30 years, and video has taught me a few things recently. The biggest problem with shooting performances is the contrast level in stage lighting. Video cameras don't have nearly enough lattitude to handle the range between light and dark in typical stage lighting. And I've come to realize that it's exactly this type of high contrast lighting that we designers really like on the stage! Now if you're in a situation where you have time to re-light the show for video then that's ideal. But if you're just walking in to shoot one performance you'll simply have to make the best of things by riding the iris as you shoot and also framing your shots to avoid high contrast areas as much as possible.

Good luck, and let us know how things work out and what you've learned in the process!
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Old May 21st, 2006, 11:36 AM   #11
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Thank you very much for the reply and advice.

It is really much appreciated.

I must say that this lighting thing is really starting to get my interest though.

I mean - have you seen (although I'm sure you know all about it) all the different DMX gadgets available - without even using a desk!

I mean to say - lighting - is an art form - all of its own!

Regards,

Dale.
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Old May 21st, 2006, 12:08 PM   #12
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My favorite "DMX gadget" at the moment is the Catalyst Media Server from High End Systems: http://www.highend.com/products/digi...g/catalyst.asp

You connect your video projectors to it, load it up with all your files, then you can program video projections directly from your lighting console, including all sorts of realtime effects. The end result is having all the video built right into the light cues. You can download the software for free (runs on MacOS X) http://www.highend.com/products/digi...aldownload.asp
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