Wave Form Monitors
Posted 09 August 2007 - 12:48 PM
Could any one please offer some advice when exposing for HD using waveform monitors. I have always been trained to use a light meter but have recently seen DP's use only the monitors with brilliant results. Any advice would be great.
Posted 09 August 2007 - 01:30 PM
Also I would recommend using a PARADE view where you can see the separate RED, GREEN & BLUE channels as opposed to only the Green or a combination for the same reason.
Think of it as a Spot Meter that reads everything in the frame at the same time...
Hope this helps.
Posted 09 August 2007 - 02:36 PM
Posted 09 August 2007 - 04:31 PM
Posted 09 August 2007 - 05:09 PM
While it's important to fully understand tools like a waveform and vectorscope or even a light meter, don't loose sight of what's important and that's the image you're trying to create. ... I realize that my example might be criticized for potentially being an issue with post, the bonding company, quality control, etc., but what a cinematographer strives for is a balance between the artistic and the technical.
I agree completely. The waveform is like a light meter for video, but doesn't replace what your eyes and experience tell you any more than it would for film. For me the best use of a waveform is just as a double-check against what I'm seeing on the monitor. If the monitor is working and set up properly, what-you-see-is-what-you-get. The waveform can verify the that the setup is correct, and confirms the actual levels in the extreme highlights and shadows. But like Eric suggests, don't fall prey to treating the waveform the way a video engineer might (worrying too much about clipping, etc.). It's just a reference tool -- you're still the artist.
You'll want to familiarize yourself with what a "normal" image looks like on a waveform monitor, so that you can recognize when your camera setup and exposure are behaving the way you want them to. For example, a properly exposed gray card generally will fall close to the middle of the waveform, anywhere between 45-55 IRE (depending on the look you're using and how you're exposing the image for post).
Posted 09 August 2007 - 08:36 PM
Everything else I do by eye, and then check highlights/shadows with the waveform, and knock those down the highlights and bring up the shadows as needed. A good tip to check the skintone level if your on a zoom lens, just zoom into the forehead of the actor (or similar target in your key light) that way the whole of the WFM is easy to read and interpret. Watch out though, since all zoom lenses, and particularly the cheaper lenses will start to loose light as you get to the tighter end of the lens, which will throw off your reading when you zoom out, by as much as a half-stop or more. If your farther than mid-focal length, just use a light meter (or shoulder the camera and move closer to get a reading. an assistent to hit the freeze button is very useful here.)
Adjust your target IRE level just as you would adjust your target f-stop reading from your spot meter in film, depending on how light or dark you want to render your subject given the scene's setting and actors natural complexion.