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Photography Question 
Charles K. Tufuor

White Balance with Expo Disc

I use a Nikon D300. Most of the time when I use the Expo Disc in a big hall, I get different results. I do not know what I am doing wrong, but the quality does not come out as it should. You obviously see that the color is different from what it actually is. What is the best way to use the Expo Disc?

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2/22/2011 5:16:49 AM

Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
  You may not be doing anything wrong. You may be in a place that has mixed lighting. And not meaning different types, as in some fluorescent and some incandescent - I mean mixed color temperatures. Even if all the lights are the same type, all fluoros, the color temp will not be the same for each light - maybe so much that it's really evident in your pictures. I'm sure since it's a big hall with a large number of lights that some of the lights can be brand new, while others are a few days from burning out.

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2/24/2011 2:29:38 PM

Charles K. Tufuor   Hi Gregory,
Thanks for your response. This hall is a school auditorium and my church worships there on Sundays between 10:00 a.m. to about 1:30 p.m. If I don't use white balance, the pictures sometimes turn out better than in an instance of using the Expo Disc. The question, therefore, is: What do I do to improve the pictures using the white balance Expo Disc?

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2/24/2011 3:37:09 PM

Gregory LaGrange
BetterPhoto Member Since: 11/11/2003
  I might be wrong, but from what I thought, you put the expo disc over the lens, aim up at the light source, and use that picture to set the custom white balance. If that's what you're doing, your problem is probably like I said. You balance off a too-specific light source in a room that has maybe 5 or 6 rows of lights with each one not being the exact same color temp.
If you're set on using the Expo Disc, how long is the lens you're using it on? If you try a wider angle, thus using more sources to balance on, maybe you'll get a balance that's a good average.
If you're willing to use something else, I've used a small piece of white ink jet paper to take white balance off of.

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2/24/2011 3:52:13 PM

Robert Williams   Charles -
As Gregory mentioned, it's probably the lighting in the hall. From your description I'm betting that the lights are the typical sodium vapor lamps used in many gyms and sports centers. The color of these lamps not only varies with age but actually varies with the frequency of the AC electricity. This means that the color shifts every second. If you'd like to prove this set your white balance to a constant setting (anything but Auto) and put your camera on continuous high and take a burst of five or so photos of the same subject with the shutter speed greater than 1/60 sec., let's say 1/250th. Now look at the photos and you'll notice that almost all of them have a slightly different color cast. There's really not much you can do about this except fix it in post. If you'd like to get as close as possible with your Expodisk, take the white balance setting shot at 1/30th or less to allow for a full AC cycle. This will average the white balance of the lights and may at least make your photos a bit easier to correct later.

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3/8/2011 8:57:21 AM

Charles K. Tufuor   Thank you Robert for your suggestion. I will it out.

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3/9/2011 5:32:26 PM

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