Calibrating Cameras Can Be Art Too
Something as simple as white balancing a camera can make a huge difference in how your video is perceived by those watching. Does your subject look orange? Blue? Green? I hope none of the above. They should look the same as they do in person. Red, yellow, black, or white.
Perhaps it’s the fact that I’ve been a video engineer for 15 years and have been in the film and video industry for over 20 years that makes me feel this way, but when I’m watching a TV show or a movie and I see scenes cut together with coloring that doesn’t match, it makes me cringe. These are professionals and they should be getting this right. When this happens, it can cause people to get distracted and disengage.
It makes me wonder if people watching video during a church service ever feel distracted when they see cameras that don’t match, or irises that don’t look properly shaded. The last thing a technical crew member wants to do is draw negative attention to the gear. If you make people aware of something going on with your cameras or videos, then perhaps they’re not listening to the pastor? Lives are at stake. Eternal lives.
There are a few simple steps you can take to get even simple cameras to “line up” together to improve your video look. It’s as easy as using the right tools, the right light, and some fundamentals of “chipping” cameras.
1. Use the right tools for the job.
When tackling a job or task, you must have the right tools. You wouldn’t take a pair of pliers and a hack saw to hang a shelf, you would take a screwdriver and a level. White balancing multiple cameras to make them match (i.e. chipping) is no different.
You’ll need a waveform monitor and/or a vectorscope. Some of these instruments can be very expensive, but if you don’t have one of these in your arsenal already, don’t worry. Final Cut and Premiere have these built in and there are several brands of monitors that offer these scopes as a part of their design.
We use Blackmagic Design’s UltraScope to calibrate our cameras. The RGB Parade waveform is what I love most about it. It simply shows the red, green, and blue values separately on the same monitor. More on this later.
2. Get the right light and the right chart.
We always chip the cameras to the preach wash with no added colors (any added preservatives are up to you). The pastor is the focal point of the service, so why not make them look the best? The lights themselves have full color temperature blue (CTB) in them. Our LD, Daniel Connell, choose this to make the preach wash closer to the true color temperature of all the movers in the rig. This way, on video, the movers themselves look closer to how the colors are perceived in real life. No camera (yet) can truly represent the colors a human eye can see. But at least this way, the cameras have a fighting chance. The color temperature our cameras read is around 4400 K.
You can spend a lot of money on white balancing charts. There are a several of them on the market. I’d like to say we bought one of these big, expensive charts, but we didn’t. In fact, I’m not even sure where we got it. Or, exactly what it is. All I know is, it works. And it’s white. Bright white in fact. We even went high tech and gaff taped some black cloth to it. Point is, you could spend a lot of money on a calibrated chart or you can find something that just works. A dry erase board, a piece of paper, or even a white t-shirt…well, maybe not the t-shirt you wear to change the oil on your ’78 Camaro. Whatever it is, just be consistent.
3. The Chip.
There are hundreds of different variations to “chip” or white balance a camera. Many people have different methods they like to use. But follow this one rule and you’ll be good: Does it look good? Yes? Then you did it right. No? Find another way. Simple. This only works if your idea of good actually IS good.
The following is what we do here at COTM. Like you have read on the Seeds blogs before, this way works for us—it may not be the way the broadcast world does it, but the cameras will look good.
- Aim all the cameras toward your chip chart of choice with the preach lights on at the level they would be used at. No added colors. As close to the same perspective/angle as possible.
- Iris the cameras so the chip chart is at 80 IRE. Some say 90. Avoid 100.
- Do any auto white/black balance your cameras may offer. Order is up to you. Several theories out there. We do white, black, and white again.
- Using the RGB Parade waveform, make all three colors the same IRE by adjusting the red and blue gain settings. Some higher grade cameras have green.
- If you have no RGB Parade, using the vectorscope, make all cameras have the same spot in the center cross hairs by adjusting the red or blue gain settings.
- Close the iris to where the chart is between 7.5 and 0 IRE. Repeat the waveform or vectorscope step again, but this time adjust the red and blue gain for the black level.
- Once all the white and black color adjustment have been made, iris all cameras to 80 IRE and switch between them to see any color differences. This is a good time to adjust the master black levels. Make all cameras read the same 7.5 to 0 IRE on the black level of chart.
In the pictures, we have our two centerline cameras shooting the same white card. Iris is set to where they are an average of 85%. A horizontal wipe is in place to allow us to see both the white card and black cloth simultaneously. Notice they have a little bit more red in the picture. This was used to warm up the image. If you wanted a true white, make them all the same IRE.
Like here at COTM, you might have some small POV cameras that don’t look like your main center line camera. I can accept that as long as it’s close. They don’t have enough handles to really dial in the colors and blacks. They may have some adjustments that can be made to the color temperature, or to add or take away some blue or red to get them close. Perhaps they have a manual white balance you can manipulate to better the colors.
4. The Aftermath.
Without a doubt, once you have studied your cameras one by one and compared side by side, when you widen out and see a stage set lit with people, you’ll want to make some final adjustments. Hopefully, not so much with color, but with the Master Black or Pedestal. Make your final adjustments with a good monitor or a trained eye. I won’t bore you with this here as there are many guides online on how to calibrate a monitor. But I do strongly recommend you calibrate your monitors so you have a solid base to work with.
For a guy who has a red-green deficiency color blindness, I have learned to trust my instruments. It all started long ago when I went through pilot training in college. During training, you spend a lot of time learning to trust your instruments. We did this in case we were ever caught in a cloud or fog so we could manage ourselves out and not go nose first into the ground. I never flew into a cloud to test this out, but we trained and trained and trained regardless.
I think back on those days every time I chip cameras. Much like my altimeter and artificial horizon that I trusted to keep my nose up and wings level, I now trust a waveform monitor. Does it help to have confidence that your instruments are telling you the correct information? You bet it does.
Ultimately, this has helped me become a better engineer. Can something this technical be part of the finished art we are creating? Absolutely. Happy shading.