I’m sitting here in my office working from home, which is pretty typical, and outside is the beautiful site of snow falling from the sky. I’m thankful that God made snow white because as it falls from the sky and begins to stick to the trees it makes everything absolutely beautiful. In fact it kind of annoys me when people post pictures and the snow is anything but white. It is this thought that has made me think about white balancing cameras and how important it is for the end viewer.
The purpose of white balancing is to make the image look appealing to the eye and to look seamless between cameras. But properly white balancing is an art, it takes time to learn, and even more to master.
When I was in school we had an old studio equipped with 3 cameras. One day my professor lined up all 3 cameras, aimed them at a chip chart, turned on the scopes and began to explain this process. All 3 cameras were identical, same brand, model, purchased at the same time, and each one was only 1 serial number apart from the last. They were the exact same cameras and even though they were older, Still worked great!
How to white Balance
Now there are 3 ways to white balance a camera. The first is to use the camera preset. This is just a manufactured white balance that is supposed to be associated with 32K lighting. My professor flipped all 3 cameras into preset mode and each camera looked significantly different. In our studio it did look white, but not perfectly white. At the end of the day there was no way this would pass when switching between them or even for customer satisfaction. This was obviously his point in this part of the exercise.
The second way to white balance is to do an Auto White. Point the camera at something white and flip a switch for the camera to auto – calibrate itself to white and then flip the switch another way to auto – calibrate itself to black (Most cameras have a preferred sequence of executing the white/black balance, consult owners manual). We executed the proper sequence for these cameras and took a look. The colors were much better! But, you could still tell that each camera was a little bit different from each other. This might pass inspection but the bottom line is they were still different.
The third way is to manually paint the cameras to match, by adjusting red and blue on both the white and black values. Using a chip chart my professor carefully painted each camera using a waveform/vector scope and got the cameras to match perfectly.
Understanding White Balancing
In order to fully understand white balancing you first need to understand color temperatures. Cameras for the most part operate in 32K or 56K color temperatures. (some new cameras have more options such as 48K). The cameras should be set in whatever mode your front lighting is set to. This is done by changing the filter on the camera to the correct mode. Most conventional lighting operates in a 32K color temperature unless you are using CTB (Color temperature blue) filters, which would change the color temperature to 56K.
Some people believe that cameras look better when the front lighting is set to CTB. This can be believed for many reasons, which I won’t get into. I personally think conventional lighting looks great on it’s own. It gives the stage a nice warm presence. CTB can tend to make the stage look stale and cold. Since I believe it is all about the audience’s experience I personally stick with a 32K color structure because it offers up a warmer look that I like better.
There are 3 kinds of looks to go for when white balancing. The first is a “True” look. This is where white looks white and black looks black. It is very technical in nature, you should use a chip chart and a scope and be able to dial them in exactly. The second look is a “cool” look. With a cool look everything tends to be more of a blue, dull look. The third is a “warmer” look. A warmer look tends to be richer in color, a bit yellower in nature. Turn on the TV during the local news and flip between the channels and see which stations have a true, cool and warm look. This is a good way to find your preference.
Overall I personally shoot to make all the cameras look warmer. This is because, a) it is my personal preference and b) with a warmer looking stage wash, I want my end product on the projectors to match as close as possible.
A quick aside to get up on my soapbox…
Cameras can be colored perfectly to one another and still look horrible if they look drastically different from the stage. This is one of my biggest pet peeves!! If you don’t look similar you look WRONG, and BAD. You pull people from their experience! Do what you can to try and make the image on the screen as close as possible to the image on the stage. This takes lots of time and will require adjustments on both the Projectors and Cameras. Nothing says Amateur like non-white balanced or poorly white balanced Cameras!
I understand that not everyone has cameras with full CCU control. Doing an auto white/ black balance may be all that is available to your camera. One strategy I have used in the past to get a warmer feel is to find different things on the stage to white balance to. A white T-shirt, Drumhead, piece of paper, or whatever else you can find white will all absorb light differently. Try it out and see how it looks, if you don’t like it, try something else. Sometimes I find shades of blue to get a while balance I like (a blueish tint helps to get a warmer white balance). Try different things and do some extreme things. Like change the iris level, add in some blue from a color wash, change stage location. Most cameras have 2 white balance settings, use both and trade back and forth until you find one that look good/ or matches your other cameras.
Believe it or not most cameras have some sort of paint menu. It may be buried so consult your owners manual but even if you don’t have a remote control you can still make fine adjustments. Even if you do have a remote, still do an auto white/ black balance. This will kind of zero out the camera to make painting easier.
Aside about black balancing…
Black Balancing is very important, I will explain why in a bit. But it is easy to not black balance, or at least not Auto black balance. After some use cameras tend loose pixels. If your camera has lost a pixel or two, be sure to give it an auto Black balance a few times in a row. Most of the time this will fix your pixel issue (not all the time, in those cases you have to send in your cameras to get pixel blended).
When manually painting a camera it is always helpful to have some type of chip chart. They can be very expensive and do have expiration dates on them as they fade over time. You can add a level of CTB over the chip chart to help paint them warmer.
If you can always get the cameras shooting from the same angle. Angles can turn different results due to how the light reflects from that angle.
I have been in many situations where I don’t have a chip chart to color cameras off of. In those cases I will use a piece of paper, or human flesh tones also work great (not for autos)
Step by step:
Note: Before painting your cameras be sure your Waveform/ Vector scope has been properly aligned. Also, this is not a tutorial on how to read a waveform/ vector scope.
After you do a Base white and black balance I always iris the cameras all the way down to black. I pull up the waveform and make sure all my black levels are uniform. Some like them crushed others like them high, I personally like them crushed just a bit. Next go to the vector scope and align the dot so it is exactly in the center.
Then Iris all cameras to the proper levels and make sure all cameras are at identical levels, use your waveform to assure exact levels are achieved.
Starting with your main camera begin to adjust red and blue while looking at your vector scope to achieve the look your are going for. It is at this point I run back and forth from the control room to the auditorium to see the stage to screen comparison. This is the artistic side of coloring.
A former co-worker of mine used to work as a Colorist in the film industry. He is by far one of the best camera engineers I have worked with and makes all the cameras look absolutely identical! His philosophy is that it is all in the blacks. The blacks really set the tone/ look of the camera image and can really show how off your colors are from one camera to the next. Spend time warming up the blacks as well as the whites in order to get the image to look as good as possible.
Once you get your primary camera looking good adjust each camera one at a time to match. Remember, it is all in the Blacks. Once you get the whites/ flesh tones looking good spend some time in the blacks, that is where you really notice it from camera to camera.
Some strategies I use when I don’t have a vector scope (of even if I do) are: using a half wipe comparing 2 cameras, use different monitors flip through cameras (sometimes really cheap or worn out monitors pull out color differences good monitors don’t see), lastly, leave the room for awhile and then come back so your eyes don’t play tricks on you.
Painting Cameras and having a good white balance is one of the most import pieces in providing your audience with a good experience. It is a very difficult skill to learn and even more difficult to master. I still have a lot to learn on the subject especially since there can be so many parameters beyond red and blue when adjusting cameras. Before each production you should be checking the colors of your cameras to be sure they look good and match one another. Don’t settle in this area, it is so important.