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Match WB Kelvin to color temperature of lamps?

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Duke Sweden
Match WB Kelvin to color temperature of lamps?
on Jul 17, 2016 at 11:39:05 pm
Last Edited By Duke Sweden on Jul 17, 2016 at 11:40:34 pm

This is more out of curiosity than anything else. Up until now I've adjusted the white balance kelvin in close proximity to where it "should" be, then adjust for taste. I was wondering, however, if I should set my Kelvin reading to 5500K since my studio lights are all 5500K color temperature.

Opinions appreciated.

btw, I've never posted here before. I'm usually in the Premiere Pro forum, so I should point out that I'm a complete amateur and do this for my own enjoyment. I don't have Scorcese looking over my shoulder as I do post on his footage ;-)


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Chris Wright
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 12:44:08 am

hi,

you're probably wondering why does any of this matter, because you can fix it in post, I'll add this little tip:

Besides the fact that you want to have a single temp for all light sources(for no dis-coloration), the closer your camera's white balance matches the actual k of the ambient light, the less banding you'll have when color correcting.(non-RAW)


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Duke Sweden
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 1:46:17 am

You again! ;-)

Come on, Chris, you know I'm dealing with h264, albeit a more vibrant version now. So I can't really "fix it in post". I mean, yeah, I can make whites look white, but that's not gonna gain back color information I'm losing by not shooting with correct white balance, right?


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Chris Wright
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 2:43:07 am

you're getting banding if you shoot 8 bit for sure which h.264 is. it's the same idea why the hue angle makes little dots ;)

with h.264, you need to check your zebras/histogram for correct black/white levels and white balance to the native kelvin of the light source whether it be bulbs or sun. if need be, its always better to up the iso than try to push it in post to recover shadows, and highlights clipped are gone forever.


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Duke Sweden
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 11:34:17 am

I'm currently not getting banding because I'm not including a large part of the sky in my shots. I'll have to do an experiment. I've mostly shot indoor green screen with the new camera so far. Never had a problem with hue angle dots ;-)

But basically you answered my question in your second paragraph. I always manually white balance with my trusty 18% gray card but I'm enjoying this new feature of adjusting the Kelvin. Since, as I said, I get it to where it should be, then tweak it to taste, I had the question about whether I should be tweaking or not.

Anyway, thanks again for your help.
Cheers!


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Alan Lloyd
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 5:00:21 pm

Unless you have something akin to a CCU tied to scopes to work with, you'll get results as good, and far easier to work with, by chipping where your subject is, with the real-world mix of light that will be falling on them, and setting your white level to around 70-80 IRE before hitting the "WB" button.


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Duke Sweden
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 7:34:50 pm

Hey, c'mon man I'm just a kid! ;-)

Seriously I play at this, I don't even know what chipping or IRE is. Chris gave me the info I needed.
Thanks, anyway. Always appreciate the big boys taking time out to help me.
Cheers!


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Alan Lloyd
Re: Match WB Kelvin to color temperature of lamps?
on Jul 18, 2016 at 7:56:42 pm

"Chipping" once referred to painting white balance with a chip chart. It now means hitting the AWB button/switch while pointed at a white surface.

IRE is the measure of luminance (brightness in strictly black & white terms) and if your camera has a zebra setting putting it at 70-80 IRE* is good - that's about where you want the brightest highlights** on Caucasian skin, exemplified by noses/cheekbones/foreheads and the like. If you cut in Premiere the waveform monitor will show you the 0-100 IRE scale on what you'd already recorded.

Not really one of the big guys, as you phrased it, I've just been around for a while.


* Don't white balance at 100 IRE/peak white. At that point you don't really know what you're balancing on.

** Since people are what I deal with regularly, I tend to optimize for recording them - rather than environments or objects. As always, your mileage may vary. (Standard disclaimers apply. Non-standard disclaimers available by prearrangement.)


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