[georgia]

Some audio / video guidelines for shooting HD and dealing with audio in the new HD world....

enjoy....

Audio/Video Guidelines for Separate Sound Recording

Record video at 23.976 fps (not 24 fps)

This is to allow a field down converter to be used. Video playing at 24 fps cannot be downconverted. If video is recorded at 24 fps, the Post facility will "pull it down" to 23.976 fps in the downconversion process. Use Internal Timecode in Record Run mode, and the "Backspace Edit" function of the camcorder if possible.This will provide continuous, unbroken timecode on the videotape. If broken timecode occurs and insufficient preroll is available, then the post production facility will either have problemsin the audio synchronizing and editorial processes, or have to make clones of the masters that have unbroken timecode. Please consult with your camera technician for details of the backspace edit mode.

IF "Time of Day" timecode is used, then always allow sufficient preroll (minimum 5 Seconds at each start) Provide at least thirty seconds of bars at the beginning of each tape. Do not clip or crush the video signal- use the "zebra" function in the camera view finder.

External waveform monitor and picture monitor are recommended. These will allow you to view exposure levels directly, as wellas giving the camera operator a better indication of focus.Watch out for bright lights or other sources that go into white clip.Be aware of the detail in the dark portions of the image, make sure that those areas are not crushed.Try to leave sufficient room in the signal for tape to tape color correction.Consult your camera technician for details and setup of the "zebra" function.

Use either a Gray Card Plus or an 11 step gray scale chart at every lighting change
Shoot the card in the main subject area, zoom to at least 1/3 full screen image of card This is not strictly necessary, however the cinematographer may find it valuable when looking at the exposure in the waveform monitor. These may also prove valuable to the editor and colorist if there are questions regarding the exposure level during the editorial or tape to tape color correction process.

Please note any special filters or exposures in the camera report
These will be noted in the downconversion/audio synchronization log file

Allow sufficient preroll when possible (minimum 5 seconds)
In the event of broken timecode, this will allow sufficient preroll for audio synchronization.

Allow sufficient postroll (2-5 seconds)
This is to allow sufficient postroll to exit the audio synchronization event cleanly.

Make sure the smart slate is in view and legible at every clap. If tail slates are needed, make sure that they are upside down and legible.

Note MOS events in the camera report
These will be noted in the downconversion/audio synchronization log file

All video is downconverted digitally at unity settings. No color corrections are applied during the conversion process.

Time Code Guidelines for Separate Sound Recording
Always use a smart slate.
Resync the smart slate frequently (at least once every few hours). If the smart slate drifts with respect to the audio timecode, the post production facility encounters time consuming problems during the audio synchronization process. Instances of timecode drift will be noted in the downconversion/audio synchronization log file

Set Smart Slate Time Code frequency at 29.97 fps, Non Drop Frame Timecode
Slate and DAT run together at 29.97 fps; the VTR runs at 23.976 fps Some productions use 29.97 timecode converted from the 23.976 code, or vice versa. Your camera rental facility should have details on equipment to provide this capability.

Record digital audio at 48Khz with 29.97 fps NDF timecode.
Always allow 5 seconds of preroll for DAT audio.
If insufficient preroll occurs, the audio cannot be synchronized during the downconversion/audio sync session, and will have to be transferred as "wild track". This causes time consuming delays both in the audio synchronization and off-line edit process. Insufficient preroll will be noted in the downconversion/audio synchronization log file

Provide at least thirty seconds of tone at -18db at the start of each tape.
This level may vary among machine types. The tone should be recorded at the standard reference level of the DAT.

For digital audio, never allow the level to reach 0db (Maximum, full scale level)
If the audio reaches or exceeds this level, there will be distortion.
Instances of this will be noted in the downconversion/audio synchronization log file

Video and Audio Guidelines for Sound on Tape HD Recordings

Record video at 23.976 fps (not 24 fps)
This is to allow a field down converter to be used. 24 fps video cannot be downconverted.
If video is recorded at 24 fps, the Post facility will "pull it down" to 23.976 fps in the downconversion process.

Use Internal Timecode in Record Run mode, and the "Backspace Edit" function of the camcorder if possible.
This will provide continuous, unbroken timecode on the videotape. If broken timecode occurs and insufficient preroll is available, then the post production facility will either have problems in the audio synchronizing and editorial processes, or have to make clones of the masters that have unbroken timecode.
Please consult with your camera technician for details of this mode.

IF "Time of Day" timecode is used, then always allow sufficient preroll (minimum 5 Seconds at each start) Provide at least thirty seconds of bars at the beginning of each tape.

Do not clip or crush the video signal- use the "zebra" function in the camera view finder.
External waveform monitor and picture monitor are recommended. These will allow you to view exposure levels directly, as well as giving the camera operator a better indication of focus. Watch out for bright lights or other sources that go into white clip. Be aware of the detail in the dark portions of the image, make sure that those areas are not crushed. Try to leave sufficient room in the signal for tape to tape color correction.
Consult your camera technician for details and setup of the "zebra" function.

Use either a Gray Card Plus or an 11 step gray scale chart at every lighting change
Shoot the card in the main subject area, zoom to at least 1/3 full screen image of card
This is not strictly necessary, however the cinematographer may find it valuable when looking at the exposure in the waveform monitor. These may also prove valuable to the editor and colorist if there are questions regarding the exposure level during the editorial or tape to tape color correction process.

Please note any special filters or exposures in the camera report
These will be noted in the downconversion/audio synchronization log file

Allow sufficient preroll when possible (5 seconds minimum)
In the event of broken timecode, this will allow sufficient preroll for off line synchronization.

Allow sufficient postroll (2-5 seconds)
This is to allow sufficient postroll to exit the off line synchronization event cleanly.

All video is downconverted digitally at unity settings. No color corrections are applied during the conversion process.
Smart slate not required when recording the sound on the HD videotape.
Provide at least thirty seconds of tone at -18db (standard reference level) at the start of each tape.
Record tone during the video color bars.

For digital audio, never allow the level to reach Maximum, full scale level
If the audio reaches or exceeds this level, there will be distortion. Instances of this will be noted in the downconversion/audio synchronization log file If the audio reaches or exceeds this level, there will be distortion. Consult your camera technician for details and setup of the audio recording.

Off Line Preparation, Separate Audio System

Down Conversion is made from each HD 24p tape to an SD 30 fps tape
Any format Standard Definition tape is available, Digi Beta or Beta SP is recommended
Both or either 24 frame and 30 frame windows may be inserted. Client specifies the location. Depending of the type of conversion, there may some limitations with window placement. In general, it is safe to put the windows below center screen, and together, if both are required. The aspect ratio can be either letterbox, center cut or 16x9 anamorphic. Client specifies conversion aspect ratio. If timecode is broken and insufficient preroll is available, a new HD clone with unbroken timecode may have to be made at this time.
In general, TPG recommends that all HD material be downconverted to an intermediate format, then that intermediate tape and the field audio tape be synchronized, and a "Circle Take Offline Master" (CTOM) be created from them.

Audio is synchronized and transferred to each standard def tape from the DAT.
The DAT is pulled down to 29.97 fps at this time (only if required).
Usually, only circle takes are synchronized and transferred. Client specifies which audio to transfer.
All circle takes are documented in a Flex file or an ALE file for off-line batch digitizing.
An audio timecode window may be added to the SD tape at this time. Client specifies window location. There are some limitations to the window location. In general, it is safe to put the audio window anywhere below center screen.

Client is delivered Standard Def tapes with sync audio and a Flex or ALE file.
A one for one relationship between the HD tapes and the SD tapes is maintained.

It is recommended that the client use and Avid Film composer for the off-line system
Avid Project must be set for "Film Mode". All cuts must be digitized as for "A Frame" film transfers. If not, Project and subsequent EDL integrity will be compromised If an Avid is not used, TPG cannot explicitly guarantee the accuracy of any 30 to 24 frame EDL conversion

Off Line Preparation, Sound on HD Tape

Down Conversion is made from each HD 24p tape to an SD 30 fps tape
Any format Standard Definition tape is available, Digi Beta or Beta SP is recommended
Both or either 24 frame and 30 frame windows may be inserted. The 30 fps video timecode is always derived directly from the 24 fps timecode, and is "A" framed.
The HD video is pulled down to 23.976 fps at this time (if required) All HD material is downconverted.

DAT Backup Tapes
DAT tapes, made from the 24p HD original, with 30 fps timecode derived from the 24 fps timecode may be made at this time for separate Audio Post Production.

No Audio Synchronization is required
Since audio synchronization does not occur, no Flex or ALE file is generated for off line use. Media may be subclipped by the Avid assist as required.

Client is delivered Standard Def tapes with audio. No Flex or ALE files are supplied.
A one for one relationship between the HD tapes and the SD tapes is maintained.
Since audio synchronization does not occur, no Flex or ALE file is generated for off line use. Media may be subclipped by the
Avid assist as required.

It is recommended that the client use and Avid Film composer for the off-line system
Project must be set for "Film Mode". All cuts must be digitized as for "A Frame" film transfers. If not, Project and subsequent EDL integrity will be compromised If an Avid is not used, TPG cannot explicitly guarantee the accuracy of any 30 to 24 frame EDL conversion

On Line Preparation

Client will deliver the Off-Line Master video tape.
Any Standard Definition format may be delivered, Digi Beta or Beta SP is recommended
Off-Line Master must have the off-line audio on Channels 1 and 2. This audio will serve as a guide track to ensure edit accuracy.

Client will deliver the final Avid cut sequence file on format of choice (CD, DVD, Zip, etc.) or emailed.
TPG will generate a 24 fps EDL from the off line project
If an Avid is not used, TPG cannot explicitly guarantee the accuracy of any 30 to 24 frame EDL conversion

Offline master will be upconverted to HD 24p.

This is to allow on-line video conform of EDL, with an audio guide track for reference.

On Line Assembly, Color Correction and Titling

On Line assembly from converted EDL to either Sony HDCam or Panasonic AJD 3700
A "textless" master is created for subsequent color correction Audio conform is optional, depending on the needs of the client and the type of project.
"As Assembled" EDL is created for Tape to Tape color correction session
"Video Only" EDL is generated in On-Line bay for color correction

Color Correction from textless master to either Sony HDCam or Panasonic AJD 3700
A "Color Corrected Textless" master tape is created from the Textless Master

HD Titling session to create the Final Master from the Color Corrected Textless Master
The Titling session must always follow the Color Correction session, since titles do not need correction.
Textless material should be added to the final master at this time.

Try to avoid moving titles in 24p
Moving Titles can have very undesirable artifacts. If the client requires moving titles, the titles must be evaluated on a case by case
basis. The general rule is, the slower the title movement, the better it will look. This is also true of rolls and crawls.

QC and Restoration

100% QC of Final Master
All problems are noted, including any technical, video or audio problems
QC list is generated for Client, and can either be delivered via hardcopy or via email.

Any restoration should occur on the Color Corrected, Textless Master
Since this is video originated material, dirt will not be a problem, so restoration would consist of boom or rig removal, logo or product removal, and other, similar type processes.
Restoration should always occur on the Final, Corrected Master to avoid confusion and duplicate work.

Cheers
geo