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Sony XDCAM EX Pro Handhelds
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Old May 3rd, 2009, 05:52 PM   #1
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Just Curious...If someone can explain this..

So I was on a shoot the last weekend, unfortunately I forgot my white balance card...luckily there was a plain white wall and i was trying to adjust my white balance...of course the auto mode was off.....just to give you an idea of what kind of environment i was in

1. White Lights on the celing (ones you would normally see in an office)
2. Floor was marble with a touch of yellow
3. Wall (top half was plain white, bottom half had a shade of green with a grey strip in the middle)

Here is what I experienced

1. Set the White balance switch to A...and zoomed in to the white half of the wall (made sure it was in focus) and pressed the ATW switch...and Got a reading of 3800K which was acceptable, but not perfect...

2. Set the White Balance switch to "preset" and within the Picture Profile 1, I set the "white preset" to 3800K; however doing so gave me a "greenish" tone in the overall picture....this was actually done with the camera with a full wide shot...

however, everything else on the camera was constant..i.e gain, no mounted light, iris was set to auto (had to do this since I was moving around alot) in the area with inconsistent light, and I was doing the white balance in the same area*

Can anyone explain the greenish tone? Thanks
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Old May 3rd, 2009, 06:04 PM   #2
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flourescent lights
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Old May 4th, 2009, 03:13 AM   #3
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A manual white balance as you did on the wall takes into account the actual light in the scene and can compensate for gaps and spikes in the colour output that certain types of light source can have. The preset setting however provides an average setting for light sources that have a flat, full spectrum output without any spikes of gaps. As Ed points out many Florescent lights have a distinct spike in the green part of the spectrum and your manual white balance will have compensated for this while the preset will not. There is a special colour matrix in the picture plofiles (FL) that reduces the green response to help when shooting under fluorescent lighting.
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Old May 4th, 2009, 12:48 PM   #4
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Thank you for your input on this matter....will definitely consider this the next time
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Old May 5th, 2009, 06:12 AM   #5
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Ask advice, I have a card WB Novoflex gray on one side and white on another, which I do recommend the manual WB? Thanks
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Old May 5th, 2009, 08:22 AM   #6
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Quote:
Originally Posted by Docea Marius View Post
which I do recommend the manual WB? Thanks
The white card, held at the position of your subject, so the flat face of the card directly faces the camera, or perhaps tilted slightly towards your main lamp or light source. Dip your exposure to about 70% off the card.

You can move the camera to the card to fill the frame - don't, of course, move the card to the camera. I've seen that happen once too often.

FWIW - A long time ago, we did a test in difficult but very common lighting conditions: mixed office fluorescent, bit of tungsten 'dirty light' and ambient overcast daylight. We used white photocopying paper (used and unused) and a rather expensive white-card from a warm cards set. The expensive white card was better. Richer, more accurate colour through mids and shadows, reds were better expressed. Having found the EX1 to be a little bit fussy and capricious when it comes to WB, I'm now even more of an unsufferable fan of expensive white cards.
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Old May 5th, 2009, 03:41 PM   #7
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The grey side should work just as well. The beauty of the grey card is that you should be able to light and expose the scene and then simply use the grey card filling at least 60% of the center frame. With the grey card you should not need to adjust exposure to get an accurate white balance, the grey should be the same level as skin tones.
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Old May 5th, 2009, 05:04 PM   #8
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There have been many posts lately concerning WB. To each his own, of course, but an investment that I have never regretted was purchasing warm cards from Vortex Media. Vortex Media: VIDEO & PHOTO Tools and Training Those, combined with Tiffen filters have given me a warm, fresh look, that I previously did not achieve. I do not agree with those who say, "oh I'll fix it in post." I believe one should obtain the best video & audio possible . . on location.
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Old May 6th, 2009, 01:13 AM   #9
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hank you for your response, I filmao balas a wedding where the white was very difficult to facut.Lumini mixed incandescent and fluorescent to natural light :-). It was also difficult to find an area with.I hope this works
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Old May 6th, 2009, 02:30 AM   #10
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Thanks for answers, we filmed in mixed lighting conditions, the EX1 is very difficult to keep WB: You have direct access to a manual setting, only the menu ... unfortunately.
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Old May 21st, 2009, 12:58 PM   #11
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I noticed and experienced bad green tint when i shoot with daylight balanced florescent lights.
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Old May 21st, 2009, 05:33 PM   #12
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Most offices go for the cheap flourescent lamps. These are Cool whites. They look daylight balanced but have a really heavy green spike. Real daylight balanced flouros are GE Chroma 50s, and a few others. I have used Cool whites on jobs but you have to make sure all the lights you are using have the same Cool white bulbs. You can use HMIs but you need to add 1/4-1/2 plus green gel to the HMIs to bring them to same balance. Most cool whites are around 4200 deg kelvin to 5000 deg kelvin with a lot of green. Also once you are ready to shoot make sure you white balance to the light hitting your subject and change lamps to make the color pleasing.
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