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

Go Back   DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds
Register FAQ Today's Posts Buyer's Guides

Sony XDCAM EX Pro Handhelds
Sony PXW-Z280, Z190, X180 etc. (going back to EX3 & EX1) recording to SxS flash memory.

Reply
 
Thread Tools Search this Thread
Old July 26th, 2009, 02:03 PM   #31
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
Quote:
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.
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply With Quote
Old July 28th, 2009, 01:28 AM   #32
Regular Crew
 
Join Date: Mar 2004
Location: NY
Posts: 186
Quote:
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?
Max Allen is offline   Reply With Quote
Old July 28th, 2009, 05:43 PM   #33
Inner Circle
 
Join Date: Jun 2003
Location: San Jose, CA
Posts: 2,222
Quote:
Originally Posted by Max Allen View Post
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.
Gints Klimanis is offline   Reply With Quote
Old July 28th, 2009, 11:34 PM   #34
Regular Crew
 
Join Date: Mar 2004
Location: NY
Posts: 186
Quote:
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?
Max Allen is offline   Reply With Quote
Old August 1st, 2009, 07:38 AM   #35
Regular Crew
 
Join Date: Sep 2008
Location: Indianapolis, Indiana
Posts: 107
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
Jon Sands is offline   Reply With Quote
Old August 2nd, 2009, 09:43 AM   #36
Regular Crew
 
Join Date: Sep 2008
Location: Indianapolis, Indiana
Posts: 107
anyone know?
Jon Sands is offline   Reply With Quote
Old August 3rd, 2009, 02:48 PM   #37
Trustee
 
Join Date: Apr 2005
Posts: 1,269
I have always thought it was 5600k.
Michael Maier is offline   Reply With Quote
Old August 3rd, 2009, 03:34 PM   #38
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
Quote:
Originally Posted by Michael Maier View Post
I have always thought it was 5600k.
I'm guessing closer to 6200-6500 actually.
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply With Quote
Old August 5th, 2009, 10:55 PM   #39
New Boot
 
Join Date: Jul 2009
Location: Los Angeles
Posts: 23
Using a blue filter

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

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

B&H Photo Video
(866) 521-7381
New York, NY USA

Scan Computers Int. Ltd.
+44 0871-472-4747
Bolton, Lancashire UK


DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds


 



All times are GMT -6. The time now is 01:24 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network