: 30 Seconds - Tone & Bars
Published : 18th November 2003
We’ve always run Tone & Bars for thirty seconds at the head
of each tape, I think it’s pretty universal. Is this still necessary?
Today’s digital equipment is far less likely to drift and I’m
not at all sure that a full thirty seconds is required even if some adjustment
Is this just a holdover from film, running a bit of stock to guard against
damage to the negative at the head/tail of the roll? Could there be a
similar problem, with more drop-out potential with video tape? Is the
thirty second rule a ghost from the days when we were constantly setting
up our tape decks?
I’m now running thirty seconds on my first tape of a job and then
ten seconds on each additional tape. Am I getting some “free” stock, or am I entering dangerous waters?
Best regards to all,
It's still very necessary. Even with digital equipment, here are some
good reasons :
Even HDCAM and D5 decks have settings that allow an
operator to override the factory preset levels. If those settings are
off, bars let you see this
instantly on a scope.
The head/tail of a tape is the most likely place to
get damaged. Don't put critical program material on it.
ABC, NBC, CBS, FOX, MGM, Universal, Sony, & Warner
Bros. all require bars at the head of delivery masters, because most NTSC
broadcast delivery is still done from analog masters. ABC, for instance,
is still D2.
Bars aren't just for tapes and decks -- they are for
monitor calibration as well, and monitors are far from stable from facility
Tone isn't just for tapes and decks -- it's to verify
the integrity of the playback chain.
Almost every video editor I know (me included) does
some stupid human trick during Tone to harmonize with it, make fun of
it, or otherwise be silly. It would take away an essential geeky moment
in the editing suite if you lost it.
HD/2K Online Editor
Santa Monica / Hollywood
I tell my Assistants that when laying Bars and Tone that they must shoot
for 30:00 exactly every frame over or under is a 6 inch putt from a "Hole
This is a display of Mastery.
B, Sean Fairburn
HD DP LA
Thanks, Lucas, Sean,
I was speaking only of field tapes, not masters; we always put :30 bars
& tone on them for setup.
I think I¹ll continue to use the :10 bars & tone on all field
tapes after the first one, with the full :30. If I do run into a problem,
I¹ll report it.
Best regards to all,
Leo, I'd strongly suggest sticking with the :30 on each and every tape,
if for no other reason than the safety factor of avoiding creases at the
beginning of the tape. What's another 20 seconds to err on the side of