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Old February 10th, 2008, 08:53 PM   #1
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Grey cards for White Balance??

Do you guy's know why several still camera photographers use a grey card to set a custom white balance? How does this impact a video camera?

http://www.pictureflow.com/products/.../purchase.html

What is the difference for still vs Video?
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Old February 10th, 2008, 08:59 PM   #2
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Sorry for the thread....
it looks like this has been hammered out in others
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Old February 11th, 2008, 12:35 AM   #3
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In fact, sometimes we don't use 18% photo grey but instead trick our camera white balance to produce special effects on the fly (rather than color correction in post):
http://www.warmcards.com/

Still, I like the double-duty use of the Clear-Star microfiber lens cleaning cloth that's 18 percent photo grey:

http://www.cleanstar.net/products.htm

For those that use an electronic light meter like the Sekonic, we can calibrate the meter using 18 percent photo grey as a reference:
http://www.sekonic.com/products/products.asp?ID=131

Regards, Michael
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Old February 11th, 2008, 08:45 AM   #4
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Quote:
For those that use an electronic light meter like the Sekonic, we can calibrate the meter using 18 percent photo grey as a reference:
http://www.sekonic.com/products/products.asp?ID=131

Regards, Michael
The Warmcards or the cloth would have been just fine.
Now you toss in a "gadget". I am thinking a little bit of money for cards and now you really got me asking questions....

What is the best? Is this meter simple to use and how does it work?
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Old February 11th, 2008, 11:01 AM   #5
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I picked up an ExpoDisc and have been very happy with it. It helped a lot this sat when the clouds were moving and the light source kept changing a lot.

www.expodisc.com
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Old February 11th, 2008, 01:41 PM   #6
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Quote:
Originally Posted by Guy Godwin View Post
The Warmcards or the cloth would have been just fine.
Now you toss in a "gadget". I am thinking a little bit of money for cards and now you really got me asking questions....

What is the best? Is this meter simple to use and how does it work?
Rehi,

It's a bit on the high-end for most, unless you consider yourself at the high-end of a prosumer, heading to become a pro, or simply love toys! Hopefully the link above, searching the internet, and the archives here will give you specifics. But in summary, it does have several advantages over on-camera zebras - here's a few off the top:

- ability to independently measure many narrow beams of light (ratio analysis)
- ability to automatically average the light over selected areas
- ability to also measure (incident) three dimensional light on the subject itself
- make your client think you're sexy and worth your seemingly high fees

My advice - don't walk, run, flee, fly and be free before the inertia drags you in with the rest of us!

Happy Trails, Michael
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Old February 11th, 2008, 10:41 PM   #7
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It's a great meter for large format photography. Particularly if you don't mind spending 30 minutes or so mucking about to find the correct exposure for each shot. I think it's bigger than some of the newest small cameras.

I also have a real antique (bought new 40 years ago) that reads a 1/2 degree spot and is incredibly accurate. It works by sliding two geared neutral density prisms in opposite directions, thus increasing the neutral density, until the reference spot matches the output of a calibrated lamp bulb and effectively "disappears". It even has a built in voltmeter to use in calibrating the bulb.

All great stufff for "very still" photography.
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Old February 12th, 2008, 06:06 AM   #8
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Quote:
Originally Posted by Guy Godwin View Post
The Warmcards or the cloth would have been just fine.
Now you toss in a "gadget". I am thinking a little bit of money for cards and now you really got me asking questions....

What is the best? Is this meter simple to use and how does it work?
It's an exposure meter. Stick your money back in your pocket; it has nothing to do with color balance. In fact, you don't need any fancy products to set or to cheat white balance.
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Old February 12th, 2008, 11:40 AM   #9
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Exactly. Great meter and I like it, but...

I wouldn't bother with it for video. Probably woudn't bother with it for most small format digital still work either.
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Old September 5th, 2008, 02:13 AM   #10
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Follow-up on light meter benefit

Rehi all,

Yesterday I was outside filming at a wicked time of day in the summer: 3:30 - 5:30PM. It was clear the sun was going to be washing out the pix at some locations, but how much and what would be the best location, etc?

Now here was an ideal situation to check out various lighting locations without have to haul out a camera, play with ND filters, f-stops and shutter speed. Within a matter of moments, the light meter not only gives quick and accurate spot reading on a hot spot (like a white building in the background), but it's soooo easy to do comparative across various points in a scene (to compare f-stop ratios). It's also a simple process to test various areas, camera angles, etc - this allows a quick way to scout the best location. The clincher was showing the client the problem with some of their favored locations - push the button, show them the numbers, and it's easy to convince them to move on to a better location (maybe next time they'll agree to shoot at the golden hour...)

Regards, Michael
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Old September 5th, 2008, 12:07 PM   #11
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Good video use for the Sekonic just occurred to me - it would be the cat's meow for checking evenness of green screen lighting.
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Old September 6th, 2008, 07:31 PM   #12
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Jim,

Yes, it's a cool toy for chromakey light balancing but here's a situation where the camera zebras are probably best. Using the light meter route, we move the light then check several points and try again. Using zebras, it's easy to dynamically move the light while watching the entire green screen and give real-time verbal feedback to the lighting person. And on the camera, bump up/down the zebra IREs to ensure the balance is uniform across the entire screen.

However, I will profess this process may not work well for everyone. If the studio is short and the camera can't get back far enough to view the entire green screen, then the light meter is probably quickest. And realistically, the lighting concern is probably most pronounced near the sides/corners of the screen which may be outside the camera range. Or perhaps the camera doesn't have zebras at all in which case the light meter can save the day.

Regards, Michael
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Old September 6th, 2008, 09:09 PM   #13
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Well, I have to admit that I never would have gotten the Sekonic for video. But for working with my 5 X 7 Linhof view camera it's hard to beat. I had the meter well before getting involved with video.
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