color bars at start of tape

[John Pale]

Not really, as the bars generated by FCP have no relationship to the signal your camera is recording to tape….however, this may satisfy your client and he may not notice.

[Pat Kingery]

yes thats what I thought – but is there any relationship between bars generated by the camera and images captured by the camera…?

[Bob Delano]

Most Post Houses put their “House Bars” at the front of the tape. Many projects have sources from more than one camera, but as the editor you are expected to color correct the scenes as needed. Back in the “Old Days” (big on-line linear suites) we’d set up the tapes t the bars generated by the camera, but would still adjust the scenes as needed – many would still be over or under exposed, need adjustments to color and hugh levels, contrast, etc. It’s just a part of the editing project. House bars at the front (and for us here they’re the bars from FCP) allow the end user to adjust the tape to what we as editors want him to see.

My last commercial edit had scenes from five seperate commercial shoots by three cineamatographers each witht here own gear, shot over three years on a variety of film stocks and telecone by different colorists/seperate facilities. Each shot had to be “dialed in” to match the overall look for the new spot. House bars at the front allow the networks to set up the tape to an established standard so what you see on TV matches what we saw in the edit suite.

As for timecode, the old standard was start blacking the tapes at 58:00:00, a minute of bars from 58:30:00 to 59:30:00, then a slate or countdown and the first frame of the show at 1:00:00:00. Drop-frame for long format shows, non-drop for commercials. Actual standards for the front of the tape differ from network to network, but follow this general approach.

Way more info than you asked for….

Bob

[John Pale]

[Pat King] “but is there any relationship between bars generated by the camera and images captured by the camera…?”

Yes.

[Tony]

Pat,

If your camera does not output SMPTE bars and instead using bogus non unity standard video and chroma levels then the color bars are absolutely useless for the purpose color bars are intended to serve.

That being primarily to establish a unity reference standard meaning what you saw in the field should be able to be recreated on the playback vtr using color bars as the alignment reference signal.

Since your camera bars are outputting non standard luminance and chroma levels they will not match the actual video material on tape which makes them useless to any editor or post facility. In such cases I would rather have a pure black signal and peak white and will use those to set up the playback and eyeball the chroma levels using a waveform/vectorscope.

If you are inputting via firewire I would not worry so much about the bars at the top of each tape since you cannot adjust the video levels during the capture process (in the digital domain it is what it is until after it gets into FCP. But if the client insist on having color bars then what the heck give it to them and let them figure out that the bars are non standard and useless.

Color bars are very useful when dealing with the analog world or other stages where a unity reference test signal is necessary to establish proper video and chroma levels for playback.

Tony Salgado

Tony Salgado