Armed with the right kind of shot, a visual effects artist is limited only by their imagination (and maybe the budget, too). They depend on us crew on set to capture excellent footage so they can overlay their spectacular effects.
As an AC, are you collecting the right kind of measurements they need?
The Believability Factor
While looking at behind-the-scenes production stills of some movies these days, you might mistake it for the Emerald City. Green walls, green furniture, and even green men in green suits.
All that green is designed to help accomplish one thing: stunning visual effects.
Even on small shoots, it’s become increasingly common to have one or two visual effects shots. They aren’t always full of green, like the picture above, but instead are designed to accomplish subtle visual changes such as removing a prop or adjusting a background.
Whether it’s animating typography right under a character’s nose or manipulating what the audience sees through the window, there are visual effects shots littered everywhere in all types of productions.
And for these effects to be successful they have to be believable — the audience has to accept the effect as part of the reality of the film or the filmmakers risk losing an audience’s suspension of disbelief.
Think about some recent effects-heavy films you saw lately. Did you notice any effects? If you did, were they believable or did they remove you from the story?
In most cases, post-production visual effects artists try to recreate or build upon the filmed reality and the more information they have, the more capable they are of selling a visual effects shot.
What Do You Need to Measure?
If there is a visual effects consultant on the set, or someone who has more knowledge than you about the intended shot, always ask them what type of measurements or data they need. Each production, shot, and setup will need different data points depending on factors involved.
Here I have compiled a few basic measurements that help to have written down:
- Focus Distance: The measurements for the object in focus. If there is a focus pull, include the beginning and the ending measurements. This is especially crucial with rack focusing.
- Lens Focal Length: Also the type of lens in case it embodies any unique properties.
- Height of the camera: Measured to the middle of the lens.
- Tilt of the camera: Measured using a clinometer — like the Clinometer iPhone app.
- Adapters, filters, etc.: Any on-camera modifications being made to the image.
These are standard measurements I will take whether or not I’m asked to just in case they ended up needing it in post-production.
It is infinitely easier for the camera assistant to take a few measurements and jot them down on set than it is for a visual effects artist to try and emulate what they think all the properties of the shot were weeks later.
Passing the Information to Post-Production
What you do with the information you gather is a choice between you and the visual effects consultants.
Some camera assistants will write necessary info on a piece of tape and place it on the slate so the information is ingrained in the actual raw footage.
Other camera assistants will simply attach all the info to the camera reports which get distributed to production and editorial personnel.
There isn’t any “one way” to pipeline the measurements into the post-production environment so talk with those involved and use a system that works for you.
Once it’s out of your hands, you’ve fulfilled your responsibility to provide the visual effects artists with on-set camera data and enabled them to make a more polished product.
What measurements have you taken for visual effects shots? If you’re into visual fx, please chime in in the comments and let us know what info you want camera crews to grab for you!
