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Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?

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David Bush
Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Dec 31, 2011 at 6:55:16 am


Yeah, she's not wearing purple facepaint that's the camera's interpretation of the some purple spot lights.

Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?

What is going on? It's happened to me twice now. Once with blue lighting and the subject looked like a smurf. And then here with purple lighting.

Is it the CCD chips? Is the color out of range of the white balance setting? Is there an option in the camera to handle this differently bc I don't think it's underexposed bc then why would it be blue not black? Are my CCDs messed up?

This is my first post on creative Cow (what a great community). Any help will be greatly appreciated, and I'll pay it forward :-)


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John Street
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Dec 31, 2011 at 4:31:53 pm

Hi,

We're having the same issue ... with our EX-3 and our PMW-350 ... it happens with all strongly-colored LED lighting ... and since LED lighting is becoming more and more popular for stage-lighting, it's really an problem for us ...

I don't have any solution for you ... I just wanted to weigh in so I can track the progress of this post as well.

We sent a couple of full-resolution sample clips from our 350 to Sony Engineers but they've been reluctant to respond with a definitive answer.

thanks,

--
John Street
http://www.inpoint.tv
Mac OS 10.6.7, FCS 7.0.3, QT 7.6.6, Mac Pro 2x3GHz Quad-Core, 16GB Ram


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john sharaf
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Dec 31, 2011 at 5:02:44 pm

I agree, it's an LED thing. I've noticed it myself on both F3 and PDW700/800's, especially with blues and purples. In my case it was LED lighting on a wall in a club behind my interview subjects, and I was able to adjust the color to something that worked; I understand that when filming an event you might not have that much control.

My suspicion is that in color modes these LED are not continuous light sources but spike in the purple spectrum.

JS



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Bob Cole
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Jan 1, 2012 at 4:34:01 pm

[David Bush] "This is my first post on creative Cow "

And a very valuable post it is. This is the first I've heard of this problem, but with the growth in LED usage it could be a big deal. Thanks.

Bob C


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Mike Peters
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Jan 3, 2012 at 12:50:56 am

Stand by everyone. I recall this happening to me in the old Betacam days. I believe it's a gamma setting in the camera. Let me check this out on my EX3 and F3 and get back to you all tomorrow.

Just pray that I remember that long ago what setting it was.

Mike Peters
Prod/Dir/DP/Editor
MVP Pictureworks, Inc.
Washington, DC
mvpeters@mac.com


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James Sapione
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Jan 4, 2012 at 3:04:52 pm

Ive seen this many times (Less using a old beta camera) Definitely the lighting. Its almost like a black light effect. Purple is the worst.

Depending on the camera (Ex1/3, Panasonic...etc) turn off your gamma setting...basically making the picture "flat" and boring. This will help alot, but depending on the intensity of light..may not solve the entire thing. So don't expect a miracle. In post, I then tweak the contrast to make the image snap back. You can also remove a bit of the dominate color.

I hate those lights and I don't know if the issue can be resolved no matter what camera you use.


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Paolo Castellano
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Jan 4, 2012 at 3:55:42 pm

[David Bush] "Are my CCDs messed up?"

Hello David,
this a very interesting post; your camera features 3CMOS sensors instead of CCDs (used by high end Sony cameras).
I saw very strange things captured by Sony CMOS cameras (nothing to say about CCD ones).
It would be interesting to see if with the same lighting a CCD camera captures the same wrong images.
Best Regards,

Paolo.Castellano@ivs.it
http://www.ivsEdits.com
-----------------------
"Post Fata Resurgo"


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Brent Dunn
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Jan 5, 2012 at 7:46:00 pm

I film live concerts with the EX-1. If I have any control, I always try to tell the lighting person to eliminate RED. It makes them look sunburnt. I've noticed the blue being saturated on people, but not as bad looking as RED. I always request some amber / yellow / soft blue / white if possible and it give me the best images in a concert setting

Brent Dunn
Owner / Director / Editor
DunnRight Films
DunnRight Video.com
Video Marketing Toolbox.net

Sony EX-1,
Canon 5D Mark II
Canon 7D
Mac Pro Tower, Quad Core,
with Final Cut Studio

HP i7 Quad laptop
Adobe CS-5 Production Suite





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John Hennessy
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Feb 7, 2012 at 11:15:36 pm

We've shot lots of live events & concerts with our EX1 where LED lighting has been a big issue. We've found in many situations red LEDs turn out orange/yellowish on the footage, regardless of W/B, gamma, anything. We've had the same result with DSLRs too. Other colours we've found to be less problematic. And flicker, dear oh dear the flicker. No amount of shutter adjustments make a blind bit of difference.

And by the way, has anyone else found that working under purple LEDs for a while, then walking outside; everything looks weird & green to your eyes? It really screws up your color perception for a while!


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Stephen May
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Feb 11, 2012 at 5:19:17 pm

David, XDCAM EX samples 4:2:0, which is shaving color information off in the acquisition. I'm not ranting, I have two EX1 cams and really appreciate their amazing versitility, etc. The sensors are 3 1/2" CMOS chips with a native resolution of 1920 x 1080, however, as I said, the information for red, and for blue is not at the same quality as green/luminance. I'm not an engineer, but in simple terms, your stage lighting scenario is a challenge in this sense, and a chroma sampling of 4:2:2 would produce better results.

But so far, I haven't said anything helpful, so here's some suggestions; if you haven't already tried this, tapping the HD-SDI output and recording the footage onto a AJA KiPro, or Convergent Design NanoFlash, or some type of HD-SDI flash recorder is a good way to improve the image, or if you're simply switching live, use the HD-SDI output to the switcher. If you're already doing that, you might consider using a picture profile where you reduce the chroma and to a degree, the contrast - record a "flatter" image, less punch. This will help acquire more informaion in the image and you can bump up your projectors in show to regain the punch, or for post delivery, use some amount of color correction to regain the punch of color and contrast. Some people use LUT's (look up tables) and later employ a curve - often called S-curve because the curve looks like an S where the blacks are crushed (a little) the mids are left alone, and the highs are bumped up again.

Obviously, converntional lighting has a different color temperature, and that would be optimal, but LED lighting is attractive to LD's for a bunch of reasons, and I am not sure how much push you have in changing the type of lighting your LD is using. I do a show that uses LED lighting and we shoot it with three XDCAM EX cameras and I did what I suggested to you but I am also part of the crew and was able to add some white convertional light on across the truss and just a little un-gelled lighting across the truss gave me a huge boost! That also brings up a final aspect of your situation, you are likely opening your iris to get as much light as you can muster, and also you might even be moving to +3db gain but hopefully not more. Adding just a small amount of un-gelled conventional light will help you to go to 0db gain and possibly close your iris back down a small bit and the green CMOS will be able to capture enough information for the 4:2:0 sampling to work better. I really hope this helps you, good luck!

Stephen

Stephen May
Keystone Media Productions
Freelance Videographer


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John Pucci
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Mar 3, 2012 at 8:18:25 pm

This is also a major problem for me as well especially with Blue. I use a Picture Profile by Oliver Neubert that works pretty well:

http://www.dvinfo.net/forum/sony-xdcam-ex-cinealta/110902-picture-profile-r...

I also have asked the lighting person to turn down the Blue channel or add white.

Out of desperation I have eliminated the Blue channel entirely when I had a Blue corona around six dancers that proportionately looked two feet wide. Looked better than the corona.

And of course down converting exascerbates the problem.

I have shot the same LED lights with my VX2000 and it looks fine.

John


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Deborah Voorhees
Re: Why is colored stage lighting creating blotches of color on my PMW-EX1? Is it like color-overexposure or something?
on Jan 23, 2016 at 3:37:45 pm

I shot a live dance event with three different cameras. Two Sonys, the best one is the FS100 to get wide shot, and used two Canon 5D's to pick up CU shots. The Canon's held up well with the LED lights (although, the image wasn't as good as the shots it took with traditional shots), but the two Sonys was terrible with the LED lighting. Does anyone know if this is a problem with ALL Sonys? I am looking at the Sony NEX-FS5.


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