big white balance calibration target
 

A pet peeve of mine is how poor many DPs are at doing white balance calibrations. They don't pay any mind to where they are pointing their calibration target, and often end up aiming it at the cast of a carpet or something nearby, and then the calibration is the opposite of whatever cast they pointed the target at.

Or they just point the camera at a white wall which hasn't been washed and was never true white. What's the point of doing that? Much better just to use the daylight or incandescent presets.

The target needs to be getting the same light as the subject we are trying to photograph, so it should be aimed upwards about 45 degrees toward the sun or wherever the main light source is (usually overheard).

In order to prevent DPs from doing bad color balance, ruining all the work I do getting the color right as gaffer, I'm thinking about getting a proper color balance target for use on set.

The features that I'm looking for are:

1. Big. a 12" card is just not big enough to fill the frame if you are shooting something human sized or larger.

2. Matte. Any shinyness will tend to reflect a cast.

3. Neutral. Obviously the material must not have a color cast.

4. Light Grey. 18% is actually a bit dark, and 100% white can blow highlights on cheap cameras, so I'd actually prefer about 40%, but other than the Robin Myers Imaging Digital Grey card I've not seen any other light grey color blancing targets.

The target that seems closest to meeting my needs is the Lastolite EzyBalance Lastolite, Manufacturer of Greycards for Colour Correction and Exposure Control. in the 20" middle size. But before I buy one I thought I'd see what others like to use for white balancing.

Re: big white balance calibration target
 

I use the white balance card from Portabrace. Its not big enough for your spec but durable and survives packing.

Re: big white balance calibration target
 

Tom, when doing your white balance you should have the camera set in the approximate position you'll be shooting from, have the white card facing the camera straight on. Set your exposure then do the white balance. Whether you are using an 18% grey or a white card will not make a difference for white balance as long as you set exposure before taking your color temp reading (which you have to do or you will not get a proper white balance).

If you angle the card you will not get a true white balance ready for the shot you are taking.

Generally though, it should be up to DP and director on whether you would do a manual white balance at all. There are many time when you would want to simply dial in the color temp depending on what you want the look to be. The most reliable way to gauge your look is to have a calibrated production monitor on set which you can use to judge your shot.

I've got the 20" Lasolite two sided card. I use it mostly for interviews, theatrical shoots, and multicam shoots where we need to match. For a lot of movie productions we will do test footage ahead of time and decide on what the setting will be with a given lighting setup.

Re: big white balance calibration target
 

Tom - thanks for getting a good discussion going over the ins-and-outs of white balance because this is one of the areas I need to work on. My kit consists of just one 6" x 9" Porta-Brace white card and it is about ready to break in half so I've been looking for something to replace it with or even add to it.

The set I've been looking at is the 6" x 9" one from WarmCards - White Balance Reference System, the large set, along with the instructional DVD. I'll be the first to admit that the card set is probably overkill for me at this stage but I like the larger size over the smaller size cards.

After reading that Garrett uses a 20" card I'm starting to have second thoughts about the 6" x 9" because the one I have seems small as one has to get it really close to the objective to get full coverage. Now my thought is to just get the Vortex DVD and a couple large cards then learn to work with them before adding more.

Again, thanks for starting these threads.

Re: big white balance calibration target
 

I have the 20" double sided Lastolite as well. Works great for me.

Re: big white balance calibration target
 

I've been happily using a 24" pop-up white/black/grey chart from Cowboy Studio. It's even got a silver reflector on the back for the occasional use as a bounce. For less than $20, I don't think you'll find a better solution.

Re: big white balance calibration target
 

I'm on the fence between the 20" and 30" lastolite ezybalance. My experience with 12" is that it's always way way too small to get at subject position with anything other than telephoto lenses, but I've never used anything bigger.

For those of you who use the 20" size, do you typically use it at subject position, and how far away is that typically from camera (lense focal length useful too if we really want to geek out over arcs of view)?

Garrett good to hear from you... I remember you using the lastolite on a few sets! I'm curious what you meant when you said

I get why setting exposure first is good, but then once you have set your exposure lets say with an 18% grey card, wouldn't you agree that then replacing the grey card with a white card would give a higher sensor value and put you into a different part of your gamma curve (80-90+IRE ), potentially one that is less flat than 50% IRE middle grey... that was what I was getting at: measurement accuracy. I agree that if we assume color balance is perfect all the way up and down the gamma curve then the grey card is not preferable to a white card, but sensors aren't perfect and I find staying as far away from the nonlinearities useful when trying to measure things.

As far as aiming the white card dead at the camera, I still mantain that is bad practice since the lights are not typically behind the camera (that would be boring flat light); the goal of the card is to capture the light color, not the subtle environmental casts that add character and unpredictability to the light from around the camera wall and floor.

Case in point, I was on a shoot with an incandescent-illuminated wall behind the camera, but subject mostly illuminated by daylight from the side. Camera department kept asking me why the walls looked blue after they white balanced, and once we angled the card midway between the side daylight and the camera all the blue cast went away.

Re: big white balance calibration target
 

Tom, first, good discussion topic. May be doing another production basics class and need to remember to cover this subject.

Grey Vs. white card should not make a difference in theory if you first set your exposure level correctly. But that's theory. The reality is that you have to understand a lot of things that are going on in modern digital cameras if you wanted to really set your color temp to make true white record as white. The reason it doesn't really matter if you use grey or white is that both contain the same relative levels of red, green and blue. Basic theory of white balance is that you are telling your camera that a given subject is equal values of RGB. If you set exposure first (which you should always set rough exposure first), then you flip it to white, you may have one channel that is actually clipping. So lets say your green is actually at 108% IRE coming off of the card, then your camera will set the white balance so that the correction for green will be too low so you end up with a magenta cast. If you used a grey card you would be ok. That's why I have gotten into the practice finding my rough exposure level and if I'm using a white card to WB I drop my exposure by a 1/3 stop to do the WB. then set the final exposure.

If you want to get super technical you would have to look at the gamma curve of each channel separately. If, your camera's curves are equal all the way then it doesn't matter if you white balanced at 100% IRE or 2%IRE. All but, most cameras don't have RGB gamma curves that are uniform throughout the range. So I always think of taking my WB around the level that is my most important range. If a dialogue scene I usually try to keep the skin tones around 65IRE so I would want my WB reading down around there.

As for the example case regarding angle, this is a situation where they were not taking a WB reading of the key light. If your subject was being mostly lit by daylight then of course you would not assume that the light on the wall would be what you should WB to. Your camera department may have noticed the wall being blue but in reality your subject would have also been blue. You just may not have notice it looking through the camera or on a small monitor. Your editor and colorist would have seen it though. You should have actually turned off the light on the back wall, taken your white balance reading, Then turned it back on and if your DP and Director thought the light looked to orange they could throw a little CTB over the light source. Your mixing light sources so either your background light would look orange or everything else would look blue.

I'll try to address your angle of the card points in the other thread but in short your goal of white balancing is not to capture the color temp of a single light source, it is to capture the color temp of the light that is being reflected off of your subject. Then you use your knowledge of color and make an artistic decision about how you want your picture to look. One of the tools you have to do this is by setting your WB to taste. This takes experience and an understanding of your equipment. I use my WB setting to get a reading of the level then I tweak to get the look. That's why I like cameras that actually tell you what they're reading for WB. I've been thinking about investing in a color meter but they are pretty expensive.

Re: big white balance calibration target
 

(bold emphasis added)

I'd be even more specific; the goal of WB is to faithfully render the color of a subject's face. Hair can go off, shoulders, background, whatever, but the faces should be faithfully rendered. Almost always.

So, yes, I'd turn off backlights for WB, if a window is acting as a kicker on tungsten front light I would flag the window source out during WB and let that highlight later go blue, keeping to the tungsten balance. I'd consider this as something of an effect shot, needs to be managed carefully.

Artistic decisions with mixed lighting temps are for experienced ops, DPs and LDs. One of Tom's other threads addresses simplifying WB for novice cam ops. For them, "don't mix color temps" is the best advice.

I always think back to the very simple guidance of broadcast engineers when teaching the basics in an introductory class: "Can I see everything? Is it exposed correctly? Is it the right color?"

And what about post correction? I'm wary of getting too effect-y in camera unless I have time for good tests and a big monitor, would rather leave as many color decisions as I can to post.

Day-to-day, I use an in-camera tungsten or daylight preset about 60% of the time, a preset will get me to post just fine in many shoots. But it depends, what works for doc/journalism is different than magazine or corporate or narrative/feature.

I bought a set of warmcards, but don't use them much, I prefer post-correction over getting too wild at a shoot. I'm glad I have them, though, they've gotten me through to the best WB I could get under stadium & parking lot lights.

Re: big white balance calibration target
 

Gentlemen. Thank you all for this discussion. As an 'amateur', I appreciate the level of detail and insight into a very basic technique. Like most 'basic techniques' there's a warehouse of knowledge with years of practice that comes with how and when to properly push the 'little button'.

Again, thank you.

Best regards,

J.

Re: big white balance calibration target
 

Right on Garett. Thanks for taking the time to do that explanation. We're totally on the same page. Sounds like you're using getting a great signal for white balance, and you illustrate why grey cards might be better than white for novices who don't know how much or even that they should drop exposure for white balancing. Grey cards don't require that adjustment so might be better for novice DPs.


As far as angling the target towards the light, that's something I've come to by personal experience and I know that the convention is to keep it flat vertical with the focal plane. Since it's not the conventional approach and I'm not an expert in white balance, I don't want to argue too hard for it, but I do enjoy debating the merits of balancing for the light versus casts.

I agree that it's often better simply turning off lights that make color casts (leaving the main light on) while doing a white balance. In the particular case I was mentioning the incandescent was intentionally warming up the daylight though, so perhaps a colorbalance without it would have yielded too warm a capture. In most cases the cast is not part of the base lighting.

Mixing incandescent and daylight seems to be a hip thing to do now what cameras can work under low levels, and we are all used to seeing DIY videos with mixed lighting on youtube so it doesn't look as jarring as it did in the celluloid days. I think that white balancing needs to keep up with this trend. In the olden days when it was either daylight or tungsten but not both, it didn't matter as much how you aimed the target because all the light was approximately the same color temp.

But when you have vastly different light temperatures coming from different directions, intentionally, then I think you need to make a decision about which is going to be white, and then aim your target at that light source.

It's all well and good to just say don't mix light, but mixed lighting (especially when architectural flo lighting enters the picture) really happens in real locations, and it is often the time that the balance target comes out because the novice DP thinks "Oh, I don't know what should be white... I should calibrate with a card". They angle the card between the daylight and incandescent and wind up with a balance that is not correct for either. Or they don't pay attention to the angle and end up with essentially a random value depending on the angle.

Re: big white balance calibration target
 

On the early '90s TV show Twin Peaks, they used mixed color temps very often. In general, the back light would be bluish, motivated from a window. The color balance is set near tungsten, giving a slightly warm overall look (they were often in wooden rooms) with a clearly blue cast on the hair/back light.

I almost always do this, when appropriate. When it's not motivated, a 1/4 CTB gives a bit of depth without being obvious. A 1/2 CTB is ideal for a subtle, motivated look. A Full CTB is quite strong. I've used this for people in a dark room watching a TV or monitor. In each case, I'll balance to the tungsten fill/key.

A mixed temp setup offers the magical possibility of making a low contrast scene look dynamic. If you light with the fill nearly as bright as the key and add a subtle hair light - all matched, the contrast will be low and the look will be flat and boring. Bring up the key or hairlight and you no longer have low contrast. However, if you put a 1/2 CTB on the hair/back light, you can keep the contrast low while adding contours that bring depth to the subject. If there's a green Exit sign in the background, use a green gel for the same effect. As always, balance to tungsten, rather than to the colored splash light.

These days, when I see a back light with no gel, I can't help but feel that the job isn't yet complete. :)

Re: big white balance calibration target
 

I thought I'd update this with a test picture that I took with all the white targets I have. Attached is a pic with:

Going clockwise from upper left:
Lastolite tri-flip white panel
Lastolite Ezybalance
An old "white" sheet
A sheet of laser printer paper
The Gretag MacBeth ColorChecker white panel (in top of black plastic frame)
RMI digital grey card on top of a cheapo clapper.
(on the bottom are the cushions of a white leather couch).

This photo was taken at daylight color balance setting on a Canon s110 camera, and color not adjusted in post.

I am glad that I got the Lastolite Ezybalance; it seems to be well calibrated to proper color balance and I am surprised how useful the cross target is for framing. However I'm not happy with the way that the Ezybalance doesn't tend to lay flat; it has a tendency to curve into a saddle configuration reflecting different colors from different directions on different corners.

Re: big white balance calibration target
 

I shoot a little chart at the head of every scene. That way I have a calibrated source to work off of for first pass color correction.

Re: big white balance calibration target
 

I don't think anyone has mentioned scopes yet. Our eyes can be deceived but the scope is always correct. There is nothing like dialing in your white balance to a tiny dot in the middle of a vector scope. One of the most simple functions of a scope. And inexpensive with todays software. You don't have to buy an expensive, dedicated piece of hardware anymore. Some of you may already have scopes and never payed attention to them. They are built into most NLE software. For me, I still use Adobe On-Location (love it).

Last week I did a home tour video for a friend of mine who is a Realtor. I have never done one before so I explained to him it probably will not look as good as the videos he was used to watching. He said "come on Steve, you have been doing this for many years, I know it will be great". I said, "exactly my point, all of that experience has taught me you do not walk into a new specialty and create magic just because you are a pro".

Guess what my biggest challenge turned out to be? White balance. He wanted the great room shot at sunset with giant picture windows open to show the lake outside. Shooting from daylight to twilight over a two hour period was the challenge I expected it to be. If you think the sun does not set quickly and change color rapidly try balancing a massive surface of walls you want to stay true with the twilight. It was a challenge to say the least! And the color of those walls has to match the other rooms that do not get sunlight but are painted the same color.

Steve

Re: big white balance calibration target
 

To be honest, I think I've always had better luck (and more consistent results) by simply using WB presets for 3200k, 5600k and 4500k for times when I need to split the difference.

Re: big white balance calibration target
 

Does anyone use the good old fashioned chip chart?
http://www.kozco.com/calibrat/gray3.html

For multiple tv cameras, we always used to use these for white balance, and also to set proper exposure by watching the vectorscope and waveform monitor. As Steven said, adjust color until pinpoint on vectorscope is in middle. Waveform stairs would read black to 100% white. With this chart, you get both white balance and exposure set.
Warren

Re: big white balance calibration target
 

Yes. I love them. But my old set I carried for years got wet on a shoot and ruined (old cardboard). The only one that survived was the grey scale card. Between that one and white cards I am OK but I would still like the whole set again.

By the way, I tried printing new ones from the internet and using pan-tone colors to print warm cards. It was not the same. The scope never lies, they were close but no cigar. I want a new set. You can't paint well with a cheap bush ;)

Steve

Re: big white balance calibration target
 

Vortex Media has activated a special promo code on their website for DVInfo members that will allow you to save 25% off the price of WarmCards 3.0 or WarmCards Jr. 3.0.

http://www.WarmCards.com/WC1.html
Promo code: DVINF0

Please take advantage of this offer soon, because it expires on November 1, 2013

Re: big white balance calibration target
 

Hey Doug,

I checked out your site. Looks good. And a great offer for DVINFO members. Since your are making cards, I am curious why you do not offer a traditional "chip set" to paint with? Wouldn't that be an easy addition to your product line?

Steve

Re: big white balance calibration target
 

The point of the white balance is to make sure anything on set, that the camera can see that is white - looks white. So if perhaps you have somebody wearing white trousers, or a lab coat, then this is what the WB sorts out - so whatever you use should be where this white object will be. If you have coloured light sources and they are designed to land on the white coat, then you don't correct this - you WB for white light, and when you add the colour, you see it. If a stab of blue moonlight comes in through a window - you don't let this impact the adjustment of whites, by killing it if necessary. White just needs to be white - we're making this far too complicated - it's basic stuff, not rocket science!

Re: big white balance calibration target
 

Hey Paul,

I don’t see anyone complicating things here. This thread and another one just like it that was started at the same time are doing what this forum does best. Guys of different levels of experience are sharing knowledge and techniques.

White balance is a basic function, and a very important one. As mentioned in this thread, it can go far beyond setting a white level once and firing away. And, once you tell the camera what white IS, it sets many other parameters off of that baseline, not just white.

For me, I despise unnecessary work in post production. I believe putting a little extra time into the set up to get BASIC functions like white balance and exposure correct is always the right thing to do. :)

Steve

Re: big white balance calibration target
 

White balance may not be rocket science, but it's not as simple as some people would like it to be. Yes, there are times when white needs to be white -- but that won't result in pleasing skin tones. The primary purpose of WarmCards is to create warmer, nicer, healthier skin tones for interviews and other types of head shots. If you compare a white balance done with a white card vs. one done with a WarmCard I guarantee you that 99 people out of 100 will say the warmer white balance simply looks better.

Re: big white balance calibration target
 

No, not easy at all to produce and then quite a bit more complicated to use. But thanks for the suggestion.

Re: big white balance calibration target
 

Now just to totally blow everyones collective minds, I did a training shoot recently with a guy who spent decades as a colorist/technician with Technicolor in LA.

According to him, adjusting for skin tones is NOTHING like I ever thought it was.

You see, skintone balance isn't actually done via the tones of the "skin." You're balancing for the color of the BLOOD in the subcutaneous layers under the surface. This is why a white balance correction for the lightest skinned Caucasian and the deepest tones of African skin turn out to be PRECISELY the same.

Just to prove the point, he did a white balance using the skintone line on a vectorscope on a photo of a SEAL on a rock. Since it was a mammal, it instantly corrected the skin tones for the people in the scene just the same.

All these years I *thought* I understood white balance for proper skin tones. Silly me.

(And kind of puts skin color intolerance in a whole new light understanding that a tiny fraction of an inch below that exterior surface, every single human on the whole planet it precisely the same fundamental hue, RED!)

Re: big white balance calibration target
 

Bill, and that's why WarmCards have been so successful for the last 13 years and are used by cameramen all over the world -- they work great for all skin tones and races.

Now, if you really want to blow your mind, EXPOSURE is also the same for all skin tones. This is why an exposure for the lightest skinned Caucasian and the deepest shades of African skin turn out to be PRECISELY the same. When I'm teaching workshops this is a hard thing for some people to wrap their head around until I demonstrate it a few different ways. Then it all makes sense.

Re: big white balance calibration target
 

Bill - your post did blow my mind! So, .... its not the skin color but the layer just underneath? Wow! This comes under the heading of "Learn something new every day." That was a very interesting and valuable post. Thanks a bunch for taking the time to write it.

Doug - LED and warm cards .... Just visited your link above again and did some looking around. I got to the yellow page "How to Set up and Shoot Awsome Interviews with LED Lights:" so you know which one I'm talking about.

I've got two "types" of LED lights: the CoolLight CL-LED600 light panels ( CL-LED600 600 LED Panel Dimmable - Cool Lights USA) and one Comer CM-LBPS1800 (Comer CM-LBPS1800 On-Camera LED Light (Sony Battery) | L.A. Color Pros) ). The CoolLight panels have one type of bulb while the Comer has two color temperature type of bulbs (6 cool and 4 warm).

The Comer light while not perfect, has a pleasing color to it and I'd put it under the heading of 'close enough for Government work' for general lighting. What they did was to have a mix of cool and warm LEDs so they complement eachother. For a portable light that one can stick on the camera and use for fill, bang-for-the-buck, it works pretty good, especially when trying to add light to an existing poor-light condition.

The CoolLight panels are a different situation. The light panels are the "flood" type and put out a light that I've tried to correct with gels but there is still see a bit of green from a spike. Offhand I don't recall which gels I used but I think they were a 1/4 + 1/8. I can't totally correct the spike out via gels and messing around with trying to get it out in post is a lot of work and I'm not good at adjusting color in post. Learning how to do color correction in post is on my to-do list.

Question #1: Are the warm cards something that will help correct the color from either or both of these two light sources?

Question #2: In the case of the CoolLight panel, assuming a WarmCard would work, would a gelled panel be better to correct to than an un-gelled one? And any comment about the green spike???

Re: big white balance calibration target
 

Hi John,

I've never used either of the two lights you're speaking about, so I can't address them directly. And I generally try to avoid mixing different type of lights (for example, tungsten with LED) or mixing different brands of LED on the same shot because the colors vary so greatly. However, with that said, I've never come across any lighting instrument or professional camera that WarmCards didn't help with getting a better white balance on faces.

If you have lights that are known to have green spikes you could try adding magenta gels to the face of them if that is convenient. But every set of WarmCards also includes a "minus green" card that is specifically designed to force the camera to compensate for lights with a green spike. Originally they were created for use in locations that have a lot of uncontrollable ambient light from cheap overhead fluorescent tubes, but I've seen them work great on problematic LED lights, too.

Re: big white balance calibration target
 

Doug - Yes, I agree with the "avoid mixing types of lights" comment and in today's world there is one constant and that is change. Tungsten lasted for a century, halogen came along, then LED, and now even the LEDs and fluorescents are changing as manufacturers try and perfect their color for consumers. In the news recently there was an announcement about a German company that has come up with another high-efficiency light source. Oh boy! What's next?

With regard to gelling the CoolLights the 1/4 + 1/8 gels are magenta. What I found was the 1/2 was too much and the 1/4 not enough but 3/8 is close, best compromise, but definitely not spot on. Not only that but the gels seem to suck up a lot of light which is a bummer.

This brings up a question: do you think by doing a camera color light balance there would be "less loss" of light when using a Warm Cards?

Re: big white balance calibration target
 

John, I'm not sure I understand the question you are asking. But if you are asking if you'd lose less light by white balancing on WarmCards vs. adding gels to your lights, the answer is yes. There is never any loss of light when white balancing with WarmCards or any other calibration target. But adding gels to your lights always dims them at least a little bit, and sometimes a lot.

If the Cool Lights are as bad as you say, I'd probably add a 1/4 or 3/8 magenta gel to get them closer to normal, and then use the Minus Green card that comes with the set of WarmCards to clean up the color balance.

Re: big white balance calibration target
 

Doug - thanks for coming back with more input.

Your assumption is correct as that was what I was asking about. This would be a good selling point; for using the cards over gelling.


I don't know if they're "that bad" or if I'm very picky.

Question: If one wants to "save" all the light one can and not have it "lost" due to using gels, why not just use the Minus Green to begin with? Note: These LED floods really lose a lot with the 3/8 Magenta gels. These lights were originally intended for use indoors.


A little background:

I doubt these pictures will help because they look different on my screen now than they did on the monitor I was using at the time, after they were taken. Also, I *may* have also color balanced them a bit. These were taken about three years ago.

Here is one sample picture:
http://www.dvinfo.net/forum/attachme...-000_0722.jpeg

Here is another sample picture:
http://www.dvinfo.net/forum/attachme...n-000_0528.jpg

Both were taken with the CoolLights but I don't remember anymore what I used for gels. The pictures on my laptop that I'm using to write this don't really show any green tint

Re: big white balance calibration target
 

I used to believe this, but it's not totally true. White balance is subjective. For an extreme example, shoot a scene 5 minutes before sunset. With the sun behind your back, look at a white building in front of you. It should appear yellow-orange, not white. If a "perfect" white balance was performed in this case, the scene would look too blue.

Re: big white balance calibration target
 

Uh, I'm kinda of the opinion that "warm cards" have been "successful" because they're a way to separate a lot of people from their money. Step back and its basically charging massive markup on something that's astonishingly (outside of marketing costs) cheap to produce - and therefore it's a WONDEFUL business model.

By nature I don't EVER try to force my field shots to achieve "a look" - it just doesn't make sense to me. In the studio, the light is fixed. And light changes so much over time during a typical outdoor shoot that if my goal was to come away with "matched lok" footage, I'd be constantly re-white balancing anyway - and potentially wasting massive amounts of time trying to match the conditions.

Waste of time IMO. (I know others feel very differently)

My priorities when I'm shooting are to achieve a properly exposed image with a white balance that's close enough. Then I immediately turn my brain to my videography and talent direction and the LAST thing I want to go back to fiddling with is field color correction.

I simply feel there are way too many things that are FAR more important for my brain to be engaged with than fractional color tones - something I can easily tweek in post - and something that's getting easier and easier to push around with modern NLE systems.

My 2 cents anyway.

Re: big white balance calibration target
 

Sunlight or tungsten lighting, I might agree with this. But not shooting under discharge lamps (HMI, fluorescent, or LED).

Color temperature numbers deal only with the blue-orange axis. They don't relate to the magenta-green axis at all. Unfortunately, many discharge lamps have green spikes. This is why people in this thread are discussing adding minus-green gels in front of LED lights -- to tame that green spike.

Most modern cameras do a manual white balance function on both the blue-orange and magenta-green axes (and perhaps more besides -- who knows?). Doing a manual white balance under, for example, fluoros, can correct a nasty green spike if your fluoros are giving one. If you just dial in a specific color temperature number, the green spike goes uncorrected and shows up in post.

You're going to correct it in one place or the other. My personal preference is to correct it at capture time. I'm almost certainly going to tweak it in post, yes. But I'd rather start from a solid base. Maybe that's just me though, IDK.

Re: big white balance calibration target
 

That's what's so great about WarmCards -- it eliminates all the fiddling. Not only do WarmCards save you or your client a lot of time color-correcting in post, they also allow you white balance quickly, simply, and very predictably on-location so you can turn your brain to the other elements of the production. There's no guessing about the white balance, you don't need to check it on a field monitor, you don't need to ask for anyone else's opinion, you don't even need have a color viewfinder to know that you've nailed the white balance perfectly when you use a WarmCard.

If you're going to take 10 seconds to white balance on a white card anyway (and you should be doing that anytime you're shooting under man-made lighting!!), then it's a no-brainer to use a WarmCard instead and save yourself the hassle of grading the footage in post to make it look the way it should have looked in the first place. Even a simple correction like adjusting the white balance in post takes extra time, and why bother if you could have nailed it at the time you white balanced on the shoot?

Most cameras that are being used today only record 8-bit video onboard the camera, and anytime you do ANYTHING to 8-bit footage in post, you have degraded the technical quality of that image to one degree or another.

Another consideration is that a lot of DP's won't be editing their own footage. Most freelancers (including myself) turn their footage over to the client at the end of the project and have nothing to do with the edit. So, unless I have a sophisticated client who requests shooting in a RAW format or with an SLOG gamma, I want to make sure the Picture Profile settings, exposure, and white balance are as close to perfect as I can get them right out of the camera. When the client looks at my monitor at the shoot, or when they take a look at the raw footage back at their office, I want them to be blown away by the look I have achieved for them and not to think, "well, it's a start, but we can fix it in post."

For anyone who takes the time to actually do a test of their own and look at the difference between an interview shot with a normal white balance and one shot with a WarmCard white balance, there's no doubt which one you and client is going to prefer.

I'll be the first to admit that WarmCards aren't for everyone, but for less than a hundred bucks they can give you a better white balance right out of the camera and save tons of wasted time in post for years and years on hundreds of shoots. Not too many products offer that kind of ROI.

WarmCards - White Balance Reference System

Re: big white balance calibration target
 

Heck, every day people pay $2.50 for bottles of exactly the same fluid that comes from the sink a few steps away - and in test after test after test, the tap water from a decent municipal system is proved to be every bit as healthy and palatable as the bottled stuff. They're buying "convenience" and I get that. But sorry, I'm not buying that "warm cards" are about convenience. I kinda believe they're about insecurity. And a lack of real technical expertise.

If a shooter feels some deep compelling need not to accurately record the light falling on any face by white balancing ON that face in the traditional way - you can simply do what a lot of us have been doing for decades when we find ourselves in light that's too cool or warm for our tastes - white balance through a scrap of 1/4 CTO or 1/4 CTB gel.

But how you spend you money is your business in the end.

So good luck.