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-   -   What do you use for a white balance? (https://www.dvinfo.net/forum/open-dv-discussion/94007-what-do-you-use-white-balance.html)

Matt Buys May 14th, 2007 11:00 AM

What do you use for a white balance?
 
I use a blank sheet of white computer paper but I need something that is waterproof and was curious what other people used for their white balances? And any guess out there if laminating paper throws off the balance?

Tom Hardwick May 14th, 2007 11:32 AM

You can white balance on anything from pure white to jet black, all you need is the absence of colour. So the best thing I find is a Kodak grey card as this will sort exposure queries at the same time. Mine's A4, but of course you can cut it into smaller pieces should you want to.

The warmcards are good, they get my vote. But if all you want to do is to white balance, then choose something neautral and use it. But, beware of using ordinary white paper, it's fine in doors under tungsten lighting, but under daylight or fluorescents it's distinctly blue because it contains the "optical brighteners" that make it look "really white", photocopy and printing paper is really bad for this.

If you want a cheap source of paper for white balancing, use fresh newsprint,
it contains no brighteners, but it does age quickly so you need to use fresh paper (i.e. not more than a week old).

tom.

Matt Buys May 14th, 2007 01:26 PM

That makes sense. I noted the other day that using the back of my son's white T-shirt produced better results than the white photo paper I had been using. But I'm confused by the newsprint. Maybe not confused, but want to make sure, that white-balancing on something like the sports section of the sunday's paper, provided there's no photos, would be better than a blank sheet of white copy paper? Thanks.

Tom Hardwick May 15th, 2007 02:12 AM

That's correct Matt, and the best thing about video is it's the great teacher. As you say, there shouldn't be any colour photos on the nerwspaper but any black ink makes not the slightest bit of difference.

So go out there and w/bal first on your 'optically brightened' sheet of paper and film the garden with a human face included. Tell the microphones what you've done.

Then w/bal on the newspaper and shoot the same scene, telling the mics what you've done. Rewind the tape and watch the footage on your TV after watching some TV (or a DVD) in the dark to acclimatise your eyes to the 'artificial light image'.

With Hifi we use our ears as the most sensitive and accurate measuring tool. With video pictures it's our eyes. But do remember that some 10% of the adult male population has some sort of colour blindness, so get your wife, daughter, girlfriend in on the act.

tom.

Matt Buys May 15th, 2007 06:52 PM

Thanks Tom, just when I think I have things figured out I realize I don't know much at all. Today at the photo store I bought a generic gray card as well as a white card. The guy at the shop said the white card would look better because gray cards were more for exposure but after shooting with all three (copy paper too) I felt like the Canon HV20's white balance on the gray card brought out more color. I don't understand it, but I'm running with it. Thank you for pointing me in the right direction.

Bill Ravens May 15th, 2007 07:42 PM

an old trick is to cut out the plastic lid from a coffee can, place it over the lens to white balance.

Daniel Epstein May 15th, 2007 07:44 PM

Auto White balance circuits basically work by adjusting the red and blue gains to minimize the chroma of the object the camera looks at. Small variations in the white or gray can change the outcome dramatically. Exposure can often be an issue so make sure the camera is exposing the white/gray properly. A slight blue in the object will give you a warmer outcome. (More blue in the object the less blue gain is needed). A slight red will give you a colder balance. I would rather have a warm white balance than cold most of the time.
Often Auto White gets rid of color more than I would like so I often use Presets to keep the color in the picture unless I am in a mixed situation where I think the Auto White is going to give me a better result. Switch back and forth between Auto white and a preset to compare them and pick one.

Gints Klimanis May 15th, 2007 08:03 PM

After several white cards, substitutes and an Expodisc, I settled on a plastic WhiBal card. Overall, it works wonderfully, and its only drawbacks are that it can be lost and marred. So, it won't be the last white balance card you'll ever buy. It will probably outlast the $40-60 you'll spend on other cards.

In my experience, most of the problem with white balance is due to incorrect placement rather than the card itself. You have to decide if you want the actual color of the light or the possible cast on your subject from surrounding objects. In some cases, it's actually difficult to get that placement, such as not having access to a water channel blocked by mud and reeds, and you know the blue sky reflecting off the water is putting a blue cast on the white pelicatn.

Eric Stemen May 15th, 2007 11:58 PM

I just ordered a 34" digital target online when I used the color corrector in premiere with the black white and grey it made a world of difference. Hopefully this will help even more.

Denis Danatzko May 18th, 2007 06:11 AM

There may be drawbacks to this, but
 
as a backup for a warm card or white card, I always wear a white shirt to a shoot, even if I'm not behind the camera. If my card or sheet of paper gets lost or damaged, I at least have my shirt to work from.

Tom Hardwick May 18th, 2007 06:48 AM

The white shirt is indeed a good idea and I too wear one to reflect back as much light as possible for my backlit portraits.

Dana Salsbury May 18th, 2007 08:37 AM

I like the coffee can lid idea, but my question is how far away does the subject need to be? When I hold something in front of the camera, it's often too close, and I have shadow problems. I try to zoom in on something, but it usually moves or is such a tiny strip of white that I don't feel comfortable with the result. It seems that the idea is to get the effect of the lighting hitting a true-white subject under that lighting. At arms length, that seems too close for me.

If black works, that's a whole new game, as there is always black at weddings. I'll try that.


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