Has anybody noticed the EX1 produces much cleaner images under blue light? - Page 3 at DVinfo.net

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Sony XDCAM EX Pro Handhelds
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Old July 26th, 2009, 03:03 PM   #31
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Originally Posted by Gints Klimanis View Post
An inaccurate white balance means that needed information is attenuated during video recording and amplified during color balancing in post processing. Such an exposure method makes more sense with equipment that records lossless information with more bits than the final output, such as Nikon DSLR's with their RAW format and nearly 12 bits/color channel of information that is usually distributed in a JPG file with 8 bits/color channel.
Does this method really work for you, or is it slightly better in situations because you typically color balance anyway?
I think you are exactly right. However, since I've been playing around with this, I've found that I tned to get some really clean images. When I export snapshots of my video as DPX files and pull them into my DPX viewer, I look at color separations and though the blue channel is more noisy than red, it's not the wide chasm it has been in the past.

Maybe it's just my mind, and perhaps the next time I take the camera out for playing around, I'll test a straight white balance against letting the image go more blue. Obviously this would only work in a scenario where I already had a surplus of blue light.
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Old July 28th, 2009, 02:28 AM   #32
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Originally Posted by Gints Klimanis View Post
What you're describing is Uniform White Balance...
While this helps with metering, I don't see how this helps as much with noise in correct exposures. It can help with clipping since that information can be warped down before clipping, but the cost of protecting the highlights is loss of protection of the shadows.
Hi Glints,

Can you explain beyond the shorthand references on that?

Was trying to follow you what you mean on the relation between those several areas. How more blue light helps metering, avoiding clipping of what information, and how it affects highlights and shadows?
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Old July 28th, 2009, 06:43 PM   #33
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How more blue light helps metering, avoiding clipping of what information, and how it affects highlights and shadows?
Not so much more blue light, but all color channels balanced. Who knows how the luminance histogram is actually calculated given the shortcuts required in real-time processing, but usually, it is after the white balance operation.

The Uniform-Balance will allow you to set the exposure with greater respect for highlight or shadow clipping. Though, this is usually at the expense of about 1/3 stop of dynamic range, depending on the accuracy of your exposure parameters. This mild underexposure protects highlights at the expense of losing shadow information. Uniform white balance requires a white balance preset to be created and loaded. I've never done this on a video camera, but I've tried this on my Nikon DSLR.
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Old July 29th, 2009, 12:34 AM   #34
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Originally Posted by Gints Klimanis View Post
Not so much more blue light, but all color channels balanced. Who knows how the luminance histogram is actually calculated given the shortcuts required in real-time processing, but usually, it is after the white balance operation.

The Uniform-Balance will allow you to set the exposure with greater respect for highlight or shadow clipping. Though, this is usually at the expense of about 1/3 stop of dynamic range, depending on the accuracy of your exposure parameters. This mild underexposure protects highlights at the expense of losing shadow information. Uniform white balance requires a white balance preset to be created and loaded. I've never done this on a video camera, but I've tried this on my Nikon DSLR.
Traditionally the different display modes of scopes have been used instead of histograms I believe. Not to say that the histogram isn't useful.

To create this uniform preset, called "scene file or camera setup file" in video cameras, you'd need to monitor the RGB channels live while attenuating each channel, yes? You should be able to do this with a scope although practically its not done since the luxury of modifying lighting to create RGB balance with a color cast instead of visually neutral white balance is forbidden in many client driven situations and of course when live.

I'm not clear on how uniform balance will affect dynamic range... highlight or shadow clipping. That's adjusted with knee, toe, black level, black gamma and with some cameras discrete knee controls for each color of the 3 channels. Agree?
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Old August 1st, 2009, 08:38 AM   #35
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so whats the ex1's native white balance, where it's not gaining or attenuating any of the channels? I would think it would be 5600k, but I've shot 5600k with -3db gain and still had very noticeable noise in the midtones
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Old August 2nd, 2009, 10:43 AM   #36
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anyone know?
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Old August 3rd, 2009, 03:48 PM   #37
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I have always thought it was 5600k.
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Old August 3rd, 2009, 04:34 PM   #38
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I have always thought it was 5600k.
I'm guessing closer to 6200-6500 actually.
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Old August 5th, 2009, 11:55 PM   #39
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Using a blue filter

Has anyone experimented with using a blue filter on the EX1 to correct for tungsten instead of doing it electronically?
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