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Alexa footage coming in with balance way off

whitebalance alexa color white balance

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#1 Dan Vidmar

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Posted 20 September 2018 - 07:26 PM

Amateur editor/color grader here. Just got some Alexa footage in that is very very gold and warm, both before and after a Log C to Rec709 LUT. I was at the shoot and everything looked properly balanced on the monitors. In fact we even have photos of the monitors from shoot day and it all looks pretty balanced. Our DP was shooting at 4300K in Tungsten (indoors) which seem quite warm to me, but he claims there's no way the footage should look as warm as it does on my end after sending him screenshots.

 

Wondering if the footage was incorrectly dumped or if it was incorrectly imported into Resolve on my end, or if shooting 4300K in Tungsten is just that warm.

 

Attached is shot with rec709 LUT applied as well as photo of the monitor day-of-shoot.


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#2 David Mullen ASC

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Posted 20 September 2018 - 08:18 PM

4300K setting for 3200K lighting is pretty warm but correctable (I usually opt for 3400K or 3700K when I want tungsten to feel warm as a key light -- I use 4300K more in mixed daylight & tungsten settings).  

 

Keep in mind that the extra warmth is more or less noticeable depending on the contrast and saturation levels.  It doesn't seem overly warm to me though in these frames.


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#3 Robin R Probyn

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Posted 20 September 2018 - 10:01 PM

Check your monitor settings then.. if all the others on set looked fine would seem to point to yours being off..also I dont really see any extreme warmth color balance wise..?


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#4 Dan Vidmar

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Posted 20 September 2018 - 11:42 PM

Thanks for the responses. To clarify - the first frame is a photo of the monitor on set, the second frame is a screenshot of what I'm seeing in Resolve. The wall behind the subject is a pure white wall. Will check my monitor if you're saying that doesn't look too warm to you both.


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#5 Bruce Greene

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Posted 21 September 2018 - 12:22 AM

While 4300k will produce a very warm image, if youve recorded in LogC it should be quite correctable. You might loose a little bit of your highlights to clipping, but not too much. If theyve exposed at ISO 200 then you could have issues, but ISO 800 should be no problem.

I recently shot a scene at 9000k with some tungsten lighting. I might have gone too far, but we want a warm scene :) A quick grade on my laptop looked pretty good, but I didnt try to neutralize it away...
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#6 Bruce Greene

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Posted 21 September 2018 - 12:25 AM

If you are having problems, can you explain your grading technique?
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#7 Dan Vidmar

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Posted 21 September 2018 - 12:30 AM

I'm having no troubles correcting it and grading it. I'm more-so just concerned that something funky happened between shooting and pulling it into Resolve. My DP also said something "doesn't look right" when I sent a screenshot.

 

It is all in Log and I'm grading from there, no LUTs. Using a pretty heavy hand on the balance and exposure nodes, but it's working fine. Maybe a touch more noise than I'd like.

 

Worth noting - we're not going for a "warm" look at all with this so I'm fully balancing this out to neutral.


Edited by D Vidmar, 21 September 2018 - 12:36 AM.

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#8 Robin R Probyn

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Posted 21 September 2018 - 02:03 AM

ah ok ..yes it was unclear that the back ground from the monitor is the same as the screen grab.. if thats what your saying.. but the monitor must have had some viewing LUT also no..? as you shot log..can you find out what it was.. with respect..sort a bit odd to shoot 4300 with tungsten if you don't want a warm look.. ?..


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#9 Dan Vidmar

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Posted 21 September 2018 - 02:32 AM

Yes, I should have clarified. Both shots are on a white cyc wall/floor.

 

The monitor had a regular 709 LUT on it. That's kind of what is confusing us - when I add a 709 LUT in resolve it looks rather warm. But day of the shoot on the monitors with 709 LUT, the image looked pretty balanced. At this point I'm thinking perhaps it was the day-of monitor that was inaccurate since it sounds like 4300K in Tungsten should actually look pretty darn warm, and not all that balanced looking.

 

And yes, either the DP mistakenly shot at 4300K or the director changed his mind. But they do not want it warm at all.


Edited by D Vidmar, 21 September 2018 - 02:33 AM.

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#10 David Mullen ASC

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Posted 21 September 2018 - 03:08 AM

Seems like a monitor problem, either the saturation and gamma were incorrect so it was making the warmth less obvious by washing it out, or the white point of the monitor was set too high so it was bluer than normal, or there was a bluer look file being applied on top of the normal Rec.709 LUT. But the DIT and the DP should have noticed the 4300K setting under 3200K lighting and corrected the camera if they didn’t want warmth.
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#11 Dan Vidmar

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Posted 21 September 2018 - 03:34 AM

That makes a lot of sense to me. Luckily it was shot in 4444 so correcting this much isn't the end of the world. Thanks for the responses everyone.


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