WB (white balance) Epic questions

[Will Keir]

Found an interesting thread today suggesting that adjusting the kelvin slider manually is not the correct way to WB.

Can someone give me a correct step by step white balancing process? I haven't had much trouble with my footage btw, just that the talk of today's thread, that was closed, was that the epic skin tones were off (magenta) compared to the F3. I'd rather take the time now to learn how to do things right then assume everything is okay and have to re-shoot my shots later.

One question I have from today's tests is: Do I WB at full open aperture or do I first expose properly then WB? Does focus matter on WB? The user key I am using to WB is called "Activate WB" set to my side handle, is this the correct option?

There is also information out there that suggests to WB from a grey card instead of a white piece of paper? What's going on here.

 

[Louis Maddalena]

I'm like barely awake since its 2am here but before I turn in I'll quickly let you know how I do it.

I hold up a white card in front of the camera, then I hold down the color temperature menu on the monitor to get the advanced menu, then I select auto white balance. If I don't have time for this I just shoot the card because white balance is easily changed in RCX with the eye dropper tool. Sometimes I just use the back side of an index card if I'm in a quick hurry and just hold it into the light real quick to be dealt with at a later time.

I always have it in focus, I think its possible to do it not in focus, but I've been confirming focus on the side of the card for years.

I've heard people say they like white balancing on a 18% grey card. I've done this a few times. I don't really care, If I have it I'll use it but white is perfectly fine for me since its usually pretty available.

Ok bed time.. (I've actually been in bed the whole time.. but sleeping time) I'm sure I'll wake up in the morning thinking "what on earth did I type" but at least you have some information for now, and I'll make it sound better when I wake up..

 

[Will Keir]

Am I alone here?

 

[Tom Gleeson]

WB

WB

Yes the slider for WB is handy and in daylight very effective as the sun is so stable. In other environments artificial lighting can be complex and variable and you really need the extra green/magenta axis as well as the blue/red axis. All can be fixed in post but if your not doing the post best to do a white balance on location as you would with any professional camera.

 

[stu aull]

I think Will is asking for the mechanics of how to do this correctly. Would be curious to know this too. Not sure if the "activate WB"means "you are NOW taking a WB" or "you now CAN take a WB"

??

Stu Aull
Alaska

 

[Will Keir]

Stu I had to warrior through this one and find the answers the hard way.

Touch and hold the kelvin menu on your 5" touch screen. This will bring up an advanced window where you can manually set kelvin, tint and a button that is basically your white balance button called "Calc White Balance" You can also do this with the side handle/redmote. Scroll to the Kelvin window and hit the "up" arrow key to open the advanced window. My tint has been +27 until tonight. Oddly enough, footage shot previously looked good.

Now people talk about WB not being important, just shoot a grey card or whatever. Or WB doesn't matter, adjust in RCX. Then others talk about the Epic having magenta in skin tones and the F3 looking nicer. Then Jim replies "WB." He probably wouldn't say "WB" if it was a simple post matter right?

Conflicting reports. Some say the kelvin rotation window is good enough for WB. It's times like this you need a mentor, someone to guide the way, someone with experience, with proof.

ASK DAVID MULLEN anyone?

Still a few question to be answered. Is focus important in WB, shooting grey cards instead of white and setting WB with aperture full open or properly exposed. Some of these are obvious but I want to make sure.

 

[Uli Plank]

Focus is not important.
Grey helps you to spot reflections.
Full open or stopped down depends on the lens, some have color shifts (see the Portland PL lens shootout).
Of course you should expose for grey.

 

[Tom Gleeson]

WB is critically important. The difference with Red is that WB can be effectively done in post. When people say WB is not important they are referring to Reds RAW flexibility that prevents bad WB being cooked into the image when shooting. Whether you adjust WB when shooting or in post is dependant on your workflow and preference. BUT it is important and it will help to maintain the images maximum dynamic range and most importantly it's a critical aesthetic component of an image.

Magenta in skin tones had a ring of truth very early in Red Colour science but with RC 3 this is a criticism that has no weight. Jim's reference to WB I think is about transcoding where a proper WB will help to maintain the images maximum dynamic range.

A tint of +27 is pretty radical glad it still looked good. Shooting under fluoroscent lighting you might end up with a number like this and under discharge or fluoroscent lighting the Kelvin rotation window is probably not good enough.

Focus is not important but exposure is important. The reference object should not be overexposed but it does not matter whether it's white or grey rather that the object is neutral and does not have a colour bias.

Hope this helps.

 

[Matthew Scott]

Great response, thanks Tom

 

[Álex Montoya]

We set RC3/RG3, adjust Kelvin between 4200 and 5600 depending broadly on the type of light we're using, and adjust tint.

I'm thinking of trying the combination RC3/RG2, since looks flatter, but right now I think it's not even possible. In RedcineX it looks like a nice option to start grading from it.

 

[Scott Crawley]

I'll post this again, but this time I will be more thorough. For those who actually read manuals, the white balance section begins on pg 61, and the procedure for performing a white balance is on pg 64 of the Scarlet manual. You can download the Scarlet Operation manual at https://www.red.com/downloads.

The only difference between white balancing a Red and any other camera is the name of the funtion. red calls it "Calc WB". Setting Kelvin alone is fine, but it is only half of the WB equation. Tint is the other half.

"Activate WB" does not do a WB, it merely moves the cursor to the WB menu on screen.

To get the camera to perform a white balance fill the frame (or the majority of the frame) with a white or grey card under the light in which you will be shooting. Don't use just any old piece of paper, or piece of shit hanging around unless you want your white balance to be skewed. Use a proper reference. Navigate to the Advanced WB menu and select "Calc WB". Voilá you are done.

 

[David Mullen ASC]

If you are shooting test charts then I think WB is important especially if using anything other than tungsten to light with. And of course starting out with proper WB in post.

If you are talking about actual real-world shooting, I rarely use WB because I rarely want a neutral white light source. The only exception is when shooting under a bunch of off-color fluorescents, etc. like in a grocery store, and then I'm just as likely to try and fix it with manual color temp and tint correction.

 

[Les C.]

I've always White Balanced with an X-Rite ColorChecker White Balance Card.

But, I've heard that Graeme prefers to use a neutral gray card so as not to pick up reflected light (I guess I can also shoot my Mini Gray Scale Card and check the WB in post - I wonder if I can use the black part of the card for setting black levels?).

I do have a question for White Balancing when shooting green screen where the green screen lights have green filters.

I always assumed that I should White Balance with the green Green Screen lights turned on.

But, in a book on Green Screen shooting, it warned to White Balance without those turned on.

Anyone know what is 'correct'?

 

[Uli Plank]

Depends on your studio.
If you don't have black walls, there will be too munch reflected green and your WB will try to counteract and skin tones will turn magenta. Since you normally light your foreground subject as independently as possible, you can also white balance for it independently.

 

[Will Keir]

I wonder if I can use the black part of the card for setting black levels?).

Are you referring to "Black Shading?"

 

[Les C.]

Depends on your studio.
If you don't have black walls, there will be too munch reflected green and your WB will try to counteract and skin tones will turn magenta. Since you normally light your foreground subject as independently as possible, you can also white balance for it independently.

I have white walls, but the green screen lights are a ways back from what I'm shooting.

Never noticed the magenta (except that my eyes get acclimated to the green lights, and everything looks strange when I turn them off), but I'll have to run some tests.

Are you referring to "Black Shading?"

Actually, I was thinking about the black level eye dropper in some program I'd used once.

Black Shading is a totally different subject.

 

[Will Keir]

Yeah, I got ya. The black level eye dropper in RedCine X correct?

 

[Les C.]

Yeah, I got ya. The black level eye dropper in RedCine X correct?

Yes, most software programs provide that. Funny - I never hear of it being used much (and I've rarely used it) - I guess the pros just judge by their eyes for the desired 'look', but ... never hurts to start with reality as a starting point.

 

[Scott Crawley]

I guess the pros just judge by their eyes for the desired 'look', but ...

Do you really think that professionals use no technique to achieve accurate color, and that they magically pull it out of their asses? Do color management systems and Macbeth charts only exist for the amateur hacks who lack the mystical sphincter? Snap out of it man, these are the tools of the trade. Learn to put them to use. This isn't rocket science. You can do it too, just apply yourself and leave this magical thinking behind. Stop pretending that good images are the product of some exclusive God given gift. This is a craft that can be learned and done well by anybody... Including you and me.

You were right about one thing; reality is a good place to start, so by all means use that black eye dropper on a real chip chart. Your color will give you love in return.

 

[Les C.]

Do you really think that professionals use no technique to achieve accurate color, and that they magically pull it out of their asses? Do color management systems and Macbeth charts only exist for the amateur hacks who lack the mystical sphincter? Snap out of it man, these are the tools of the trade. Learn to put them to use. This isn't rocket science. You can do it too, just apply yourself and leave this magical thinking behind. Stop pretending that good images are the product of some exclusive God given gift. This is a craft that can be learned and done well by anybody... Including you and me.

I do believe that some people, after using their equipment for a long time, can just 'feel' if things are 'right', but ... that's after a lot of very hard work.

I remember a joke about Picasso. He painted a sketch for a tourist and then asked a number of thousands of $$ for it. She replied, "but, that only took you 5 minutes!" He replied "no, madam, that took me a lifetime".

Color management is a pretty complex topic. I started using a 'linear' workflow a while back for 3D animation lighting and in Fusion when compositing, but ... there's alway more to learn. In fact, as I learn new things, I have to re-learn a lot of the old things I used to know.

From a very old 'All in the Family' episode (which probably dates me a bit, and a bit insane to look to Archie Bunker for philosophy, ha ha), "Every man is my master, in that I may learn from him".

How do you use Macbeth charts in your daily workflow - and color management techniques are most relevant to you?