THINGS YOUR MOMMA FORGOT TO TELL YOU
A short tutorial and some Learned Advice
Okay, so you’ve just finished your film and now it’s time to edit in a digital workstation or DAW. What you may not know is you are now entering the World of Video. This is a strange place where the clock runs precisely one tenth of a percent (-0.1%) slower than the “Real” world. Why is this? When color television started broadcasting in the 1950’s, there were quite a few black and white TV’s out there. In order to not make them obsolete, a “Compatible” system was implemented so both color and black and white sets could receive the same broadcasts. The reason for this is really complex, so just go with it. When the film image is run on a telecine and converted into a video file, it must be slowed down that 0.1% or the picture will slowly “Roll”, obviously unacceptable. This process is called pulling down for video. This then is the speed at which the workstation will run; video speed. In order for the live sound recorded for the film to be in sync in the workstation, it too has to be pulled down -0.1% when it is loaded into the DAW.
Great. All set. Edit and mix away!
So, all the editing and mixing is done, and the sound and picture are in perfect sync in the WORKSTATION, but ultimately, you want a sound print on film from the sound you have just mixed, back in the real world.
Scenario #1 (Recommended): Copy the mixed sound file from the DAW to a DVD-ROM, CD-ROM, or Audio CD unchanged (at video speed) and you’re good to go for the transfer studio. Wrong speed? No problem as the studio can easily go +0.1% during the transfer to film. This process, logically enough, is called pulling up or pulling up to film speed. Files should be .aif or .wav format, 16 bit 44.1 or 48 kHz.
PLEASE no MP3’s as the quality is not good.
Scenario #2 (Not Recommended): Copy the mixed sound file from the DAW to a DVD, CD-ROM, or Audio CD using the pull up feature in some DAW’s to increase the speed by 0.1%, bringing the file back to film speed. Only problem; this could be another way to lose sync if done incorrectly, but it’s your choice!
Scenario #3 (Not Recommended): Copy the mixed sound file to a DAT tape, either pulling up or not, as in Scenario 1 and 2. DAT tapes can be recorded with timecode, a very accurate “Counter” to uniquely identify every frame of sound. Again, timecode corresponds to video or film speed. In video time, use 29.97 NDF (Non Drop Frame) timecode, for film time use 30.00 timecode. Obviously, this adds another complication and possible source of loss of sync to the process. Also, DAT tapes are on the way out! Unless you are knowledgeable about DAT’s and are comfortable with timecode, go for the audio file on DVD/CD route it’s simpler and cheaper.
It is most important for the filmmaker to provide accurate information to the transfer studio on the disc or tape or in the instructions to avoid a pull up not being done when needed, or being done twice!
Causes of loss of Sync:
Finding out that your film is out of sync after an answer print is made is very costly in both money and time! You can take out an “Insurance Policy” by doing two things. Have the transfer studio make a check magnetic film, or mag, and the lab make a silent answer print. These can be run together in sync on a flatbed or interlock projector to make sure everything is as expected. I strongly advise that the transfer studio make the mag as it can be made exactly the same way as the optical track will be made and it will be of good quality. This “Dress Rehearsal” can also expose a myriad of other possible sync problems. It also serves as an analog protection copy in sync with the picture, an extra benefit! Also very important: A sync beep at the head of the sound file corresponding to the “2” on the Academy leader will ensure that pix and sound can be aligned correctly at the lab for printing. This is the correct and professional way to sync sound and picture in the Film World.
Whew! It Syncs!
Great! Call the transfer studio and order your track. They can make it from the audio file provided in the same way the mag was made. Nothing could be simpler.
If your mag and film picture don’t sync up:
As a general guideline, a slow drift out of sync is symptomatic of an incorrect pull up/down while the picture negative being conformed incorrectly would cause a sudden loss of sync, permanently, for just one scene, or both. Conforming is a labor-intensive job and mistakes can happen! Of course, there are many other ways to lose sync!
A Quick (and Cheap) Fix: You might get lucky! If it is possible to correct the sync by editing the mag, the transfer studio can use it to make the optical track. A small loss of sound quality is possible, but insignificant when going to a 16mm optical track.
If time (and budget) allow, identify the problem, fix it, and get another mag. If you assume that everything will be OK after the changes, you could be letting yourself in for more trouble and expense!
The Home Stretch
A 16mm optical track has two possible “Winds”, A and B. If you are making a print from your camera original, a B wind track is required. This will almost always be the case for student and low budget films. “Wind” has to do with which way an image appears correct when you look at it, either through the film base or the emulsion facing you. The optical sound track wind needs to be the same as the picture used for printing. If you’re not sure what you need, the lab can tell you. Please, if you have questions about anything, don’t be bashful, ask away!
One other thing to consider. There are differences in how different labs print that effect settings for making optical soundtracks. The transfer studio needs to know where your print will be made in order to optimize exposure for that specific lab.
To summarize:
1. Make a digital sound file of the mix from the DAW on CD, DVD, or DAT.
File format .wav or .aif, please no MP! 16 bits is fine at 44.1kHz or 48 kHz.
2. Note clearly, File pulled up @ film speed or NOT pulled up @ video speed.
3. Have the transfer studio make a mag for you to check sync.
4. If mag syncs, call transfer studio and order track, specifying A or B wind and what lab is printing your film. Track will be made from your digital audio file.
5. If mag does not sync and you are out of time or money, cut mag to sync and return to transfer studio. Track will be made from mag.
6. If time allows, identify problem, fix it, and provide new sound file to the transfer studio. It is recommended to make a new mag. If it syncs, call in your order, track made will be made from the digital audio file.
That’s It!
Why do some MP3s and AACs sound like crap?
While some people may consider it sexy to transfer their CD collections onto their ever more spacious hard drives, some elementary familiarity with the compression process will help to prevent the disappointment a friend of mine experienced after he digitized his entire CD collection and then gave it away to his nephew. Turns out he compressed most of his collection at a very low data rate, resulting in rather awful sounding music. Both MP3 and AAC are lossy compression methods. A standard44.1 khz / 16 bit CD translates to a data rate of a little over 1400 kbit/sec. Thus it stands to reason that encoding at a rate of 64 kbit/sec will be a very pale imitation of the original sound. Most converters allow for the bit-rate to be set over a pretty wide range. Experimentation with various data rates for different types of music will allow the user to make an informed decision about the trade-offs between smaller size and better quality.
Questions, Suggestions and Corrections
Flash Player Required
iMadNess Interactive Media