Tuesday, February 8, 2011

Shooting Ratios

I'm shooting more than an hour a day on a feature. That's the equivalent of 7-10 rolls of film. That's what I figure. I dunno.
The new thing over the next several years is going to be the average levels of (especially) TV shows. Nobody seems to know what the average level of a program really means but Dolby has an expensive box to measure it.
My whole thing is that I don't know how long we're talking about when we say "average". How long should we be measuring RMS to determine the average level? Peak levels I got. Never go above 0dBfs. Or in the world of broadcast then maybe -12dBfs or whatever.
Joe Chapman is responsible for sending me this image.
Movies you may have missed is a very amusing blog/review/'cast thing.


joe said...

do NOT stare at DUNECAT while listening to Tangerine Dream or you will begin to bleed from your nose, eyes, and ears - it just happened to me!

Andrew Bellware said...

I just looked into Dunecat's eyes and then I could see time. All the pathways. Everything that could happen.
Unfortunately later on I forgot.

Chance Shirley said...

The Dunecat is great.

As for peak levels, I still don't understand that stuff. And why does broadcast waste the top 12db of digital audio bandwidth? I'll NEVER understand that.

If there were actual agreed-upon, published standards for DVD and broadcast stuff, that would be a nice start. Maybe there are, but I've never been able to find them on the internets.

Andrew Bellware said...

Call up Tomlinson Holman and ask him why levels are set that way!

85dB SPL is -20dBfs in the theatrical world.

The only reason I can think of for that is that if you multed all 5.1 tracks together it's very unlikely that you'd exceed 0dBfs.

The reason broadcast is so messed up is (I think) because of the way that Sony made the early digital machines. The analog output of those machines at 0dBfs was like +22 or +24dBu or dBm. So those levels were maybe about 12dB too hot for broadcast the way they had the analog part of their signal chain calibrated. Since video engineers really don't give a damn about audio except when it interferes with their video signal, I suspect that's where the standards came from.

Andrew Bellware said...

What I mean by that is that they know that they clip the transceiver on the satellites at maybe +16dB in their analog side. Since the machines could output MORE than that, they just said "The max level is -12dB" rather than just turning down their distribution amplifiers and recalibrating their audio to handle a digital stage.

And yes, this is one of the most irritating things evah.