Document 9

Celluloid Photochemical Finishing

(excerpt from Cht. 19, V&V 1e) From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

The following discussion of the photochemical process for finishing on film is from the first edition of Voice & Vision (© Mick Hurbis-Cherrier and Focal Press, 2007).

Shoot: Film / Edit: Digital / Finish: Film / Release: Film and DVD

answer prints & telecine log videotape with timecode & edgecode color correction

process and telecine film negative negative cutter printing from A & B (3 : 2 pulldown) NLE conforms negative rolls / optical master

EDL audio original video dailies release prints resolve and sync (edit decision list) audio (lab or NLE) optical master

mixed audio nonsync audio resolve audio (lab or NLE) = lab service (on DAT)

So, you want to shoot on film, edit on an NLE system, and finish the project back to film - and you want to do it the “old fashioned way.” The photochemical finishing workflow isn’t really all that old, it’s just quickly disappearing – and it is by no means obsolete yet. Shooting and finishing on film requires two format conversions. The first format transfer is the same film-to-tape transfer process discussed in Chapter 19 of the Voice & Vision book. This is how you get your footage into a digital format for editing. All issues of pulldown, sync drift, etc. apply to this workflow as well. However, when the editing is over and you need to then the transfer back from your digitally edited version, into a film print, you will require extensive services from a film lab, a negative cutter, and quite possibly a head-shrinker.

The Picture Path

The first part of this workflow is similar to workflow in figure 19-25 (in the book): shoot film, edit digital, however, the image portion of the second conversion doesn’t go from film selects to a digital intermediate; rather, all of the creative decisions you made during the digital edit are then manually From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

duplicated, cut for cut, with your actual original camera negative. Once this is accomplished, we can then strike film prints, from that edited and spliced original negative, for exhibition. This duplication of the creative decisions you made is accomplished in two steps, the matchback step and the conforming step.

Figure 1 Matchback: Matchback is the process by which the edgecode numbers on the original camera negative are coordinated with the timecode numbers on the DV transfer, so that the creative edit decisions we made in the NLE system can be replicated on our camera original film, cut-for-cut and frame-for-frame. The first step to the matchback, during the telecine transfer process, is to have the lab begin creating an edgecode/timecode database called a

telecine log (also called a Flex File) ().

The telecine log database compares the original

footage edgecode numbers (either latent image

numbers or the proprietary film barcode

system) and the newly generated timecode

numbers on the transfer in order to keep track

of each and every “phantom” frame and field

created in the 3:2 pulldown process. The lab

will give you the telecine log as a text file on

Fig 1 disk. Then, once you’ve captured your footage

and transferred the telecine log database into your project file, you are free to fully engage your creative brain and edit the movie. When you have no more cutting to do, and the editing is done, the matchback begins. Each edited shot begins and ends on a specific timecode number. All professional editing software, like Avid or Final Cut Pro, can From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

easily print out an edit decision list (EDL), which is a list detailing the beginning and ending timecode numbers of each and every shot in your movie. However, a timecode EDL includes all of those phantom fields inserted during the 3:2 pulldown process. So, all editing software designed to accommodate film shooting has a matchback tool (e.g., Avid’s Film Scribe and Final Cut Pro’s

Cinema Tools), which uses the information in the telecine log to compare the timecode EDL with the negative film’s edgecode numbers and interpolates the data to create a corresponding, frame-accurate, film edgecode EDL. This EDL now corresponds (or has been matched back) to the edgecode numbers from your camera original negative and tells us exactly which frames of film begin and end every shot in the movie. This list also includes the information for the visual transitions between shots

(straight cut, dissolve, fade to black, etc.). This list is called the matchback cut-list because it essentially becomes the roadmap for the literal cutting of the negative during the next step, conforming (Figure 2). Fig 2

Avid Cut Lists Project: AX Matchback List Title: 35mm Matchback 35mm Matchback 10 events handles = -1 Picture 1 0 dupes total footage: 74+04 Assemble List 0 opticals total time: 00:00:49:13 Conforming: Conforming (also ------Footage Duration First/Last Key Address TC Cam Roll Sc/Tk Clip Name

1. 0+00 10+04 KW 42 9137-4866+15 06:22:47:24 A85 A10G/2 A10G/2 called negative matching) is the 10+03 KW 42 9137-4877+02 06:22:54:18 2. 10+04 8+04 KW 35 3532-5791+11 06:18:07:29 A83 A10B/1 A10B/1 18+07 KW 35 3532-5799+14 06:18:13:13 process by which we cut and splice 3. 18+08 11+08 KW 42 9137-4884+05 06:22:59:11 A85 A10G/2 A10G/2 29+15 KW 42 9137-4895+12 06:23:06:29 Matchback lengthened the tail of the clip by 1 frame. the camera original negative film to 4. 30+00 12+04 KW 35 3532-5812+01 06:18:21:16 A83 A10B/1 A10B/1 42+03 KW 35 3532-5824+04 06:18:29:20

5. 42+04 5+06 KW 42 9137-4904+14 06:23:13:03 A85 A10G/2 A10G/2 match, frame-for-frame, the cuts 47+09 KW 42 9137-4910+03 06:23:16:20 Matchback shortened the tail of the clip by 1 frame.

6. 47+10 4+00 KW 46 7331-2663+04 06:25:54:15 A87 A10K/1 A10K/1 made during the editing process, so 51+09 KW 46 7331-2667+03 06:25:57:04 7. 51+10 2+09 KW 42 9137-4914+01 06:23:19:06 A85 A10G/2 A10G/2 54+02 KW 42 9137-4916+09 06:23:20:26 that we can make high-quality film 8. 54+03 10+11 KW 35 3532-5907+07 06:19:25:04 A83 A10C/1 A10C/1 64+13 KW 35 3532-5918+01 06:19:32:07

9. 64+14 4+12 KW 42 9137-4926+01 06:23:27:06 A85 A10G/2 A10G/2 prints directly from the original 69+09 KW 42 9137-4930+12 06:23:30:10 10. 69+10 4+10 KW 35 3532-5923+00 06:19:35:15 A83 A10C/1 A10C/1 74+03 KW 35 3532-5927+09 06:19:38:16 footage. Because there is only one (end of Assemble List) original negative, which is vulnerable to damage, this process is done by trained professionals, called From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

negative cutters (Figure 3), in special,

filtered-air clean rooms to ensure that your

precious negative remains free of dust and

scratches. Should your negative get scratched,

that mark will appear on each and every film

print or DV transfer made from the original.

Negative cutters match your creative decisions

to the original footage by using the telecine log Fig. 3: A negative matcher literally cuts film and then uses cement glue and a hot splicer to connect the shots. and matchback cut-list data and literally cut and glue the film together from the negative, performing the edits with cement splicing glue for a strong and permanent bond. This is the reason that this step is done at the very end, after all creative editing decisions are settled once and for all. You cannot go back after the film has been conformed and say,

“Uh . . . can you just add three more frames at the end of that shot?” Can’t be done.

Usually, negatives are cut by alternating consecutive shots onto two strands, called A&B rolls

(Figure 4); odd-numbered shots are on the A roll and even numbered shots are on the B roll. The

“missing” shot on each roll is replaced by black leader. When the lab makes a print from the A&B rolls onto a single strand of film, the A roll is threaded up first and printed by pushing light through the negative onto the print stock in a contact printer (Figure 5).

A 1 3 5

B 2 4

1352 4

Fig. 4: By printing the alternating shots on the A&B rolls onto a new strand of print film, we get a print with no physical splices. From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

The odd shots are now rendered as positive

images, but the areas of black leader protect the

print stock from exposure. The print film is

then rewound to the beginning and the B roll is

threaded up and printed, filling in those

unexposed spaces with the even shots.

However, where you have two shots that must

overlap, as with dissolves and superimpositions, Fig. 5: A contact printer like this one is used to print A&B rolls onto a single strand of film. the print film is indeed printed over twice (Figure

6). In the case of dissolves, the printer light fades out at the end of the outgoing shot and fades in at the head of the incoming shot on the next roll.

A 11

B 2

24 frame dissolve 1 2

Fig. 6: Dissolves are achieved by overlapping shots on the A&B rolls and adjusting the contact printer light during the print process: fading out the outgoing shot (1) and fading I the incoming shot (2),

A&B rolling, also called checkerboarding, allows the lab to print transition and visual effects, like dissolves, superimpositions, titles over images, and fades. It also ensures that there are physically no image-to-image edits that require overlapping a tiny portion of the frame when cement-splicing and can lead to noticeable splices. Checkerboarding ensures “invisible splices.” The printing process also allows for extensive color and exposure correction by controlling the color and intensity of the printer light. From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

Most negative cutters like to have a video copy of the film to double check each cut when in doubt.

Some prefer a video copy that displays the timecode and corresponding edgecode numbers right on the screen. Depending on your lab, it is possible to get DV copies of your footage, called window dubs, with the actual T.C. numbers and edgecode numbers burned in the image (Figure 7). Editing with window dubs can help you manage the process of going back to a film print, but you cannot get rid of the numbers, so this footage is useless for mastering on DV.

Fig. 7: Window dub with burned-in timecode (left) and edgecode numbers (right). From Andrew Lund’s Snapshot.

The latest development in the film-to-

digital-to-film matchback/EDL process is

the recording of exact barcode edge number

information (e.g., Kodak’s Keycode or

Fuji’s Mr. Code) written as meta-data directly into the data tracks of the DV transfer. With this you theoretically can capture your footage into your computer using a “reverse telecine” process, which captures only the original 24 fps frames.

All of your editing can then be done in the computer at 24 fps and a direct edgecode cut-list can be quickly and accurately generated for the conformer.

The Audio Path

Just as the image requires two conversions to go back to film, so, too, does the audio. Like the picture, the first step in the process, getting your field audio synced and into your NLE system involves the same film-to-tape transfer and syncing dailies process as discussed in Chapter 19, with all of the same issues of pulldown, sync drift and audio resolving. However, when the editing is over and you need to then move the audio into the realm of film printing, there is another conversion

From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

process necessary to reestablish sync between your audio (now including many edits and tracks of sound) and the film print, which will now be running again at 24 fps.

After all picture and sound editing has been completed (called picture lock) and your sound mixing has been completed you will send the final audio mix track to the lab (check with your lab for proper format delivery) and they will perform a reverse resolving process called pull-up. It makes sense that if audio pulldown slows the rate of audio 0.1%, to match the slowed rate (23.976 fps) of the transferred image, then when the image goes back to film (24 fps) the audio needs to be pulled-up again (sped up) to 100% speed, to sync with the film. Your film lab will do the pull-up conversion while they transfer your audio from the DAT tape (the digital world) to an optical master (film world).

Motion picture film projection predominantly uses an optical sound track, which is an analog audio system in which the film’s sound track is represented by a clear stripe of varying widths, which is photographically printed right into the black edge of the film. An exciter lamp pushes light through this clear stripe and onto a photodiode. Changes in the width of the stripe create varying pulses of light hitting the photodiode, which in turn transforms the fluctuating voltages into analog audio. The concept is not unlike the jagged grooves of an LP record, only created and read with light instead of with a needle, and this would be a pretty good metaphor if LP records still existed! Another very common option is to create Dolby Digital audio tracks (5.1 audio). In this case, your mixed audio track files must first be shipped off to Dolby labs who do the conversion from your digital files to an optical impression. Dolby labs then sends these Dolby optical tracks to the lab for printing onto the negative optical sound master.

The optical master is printed on a strip of film all on its own and then, after both the A roll and B roll have been run through the contact printer and printed onto the print stock, the film is once again From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

rewound and the optical track is threaded up and printed on the same strip of film. In the end, the print film has been exposed three times, once for the A roll, again for the B roll, and a third time for the optical track. Finally, the image and sound are photographically and permanently joined onto a single, projectable strip of film called a married print (Figure 8).

There are several versions of married prints. The first time you print the A&B and optical tracks onto the film, you get what is called an answer print. This print is used for evaluation. The director is now able to see the finished film, projected, on the big screen for analysis.

If there are any corrections that need to be made to the color or exposure, these are noted and executed during the second printing (again from the original Fig. 8: Optically printed soundtracks on a married 35mm film print. (a) Dolby Digital audio and (b) stereo optical tracks (Image courtesy of A&B and optical rolls). Once again, the Adakin Productions) director checks this print out on the big screen. If there is still more work to be done, then this print is your second answer print, and the lab will go back to the original rolls with your notes again and print another one. If all is well, then you are the proud owner of a release print—ready for distribution and exhibition.

Finishing on tape and finishing on film are not mutually exclusive. It is entirely possible to finish your project on HD and DV for mass distribution and then, when the need arises (e.g., a producer needs a film print to put your movie into theatrical distribution), you can always go back to your From Voice & Vision ed. 1, Chapter 19 (© Mick Hurbis-Cherrier and Focal Press, 2007)

negative to create a film print. In other words, always finish on tape—it’s inexpensive, it greatly expands your exhibition possibilities, and it’s the easiest format to send out to festivals, production companies, producers, or your mom.

Attention—Hidden Cost Alert!!

If you plan to shoot film, edit digital, and finish on film, you should always consult

with the film lab and the negative cutter way ahead of time to determine what they

need from you to perform a smooth matchback, and what they charge. There are two

things to keep in mind when employing this workflow. The first is that effects, like

dissolves, wipes, superimpositions, color effects, motion effects, etc., are so easily

created on an NLE system that we hardly even think about it while we edit. But if you

plan to go back to film, every one of these transitions and effects is a billable lab

process. When creating a film print, most labs charge you a per-foot fee and an

additional fee for each transition or special effect. Creating a 48-frame dissolve was

just a minor mouse movement in digital editing, but in film printing it can cost you

$20 for each dissolve! Second, talk with your negative cutter to find out what they

need from you to do the matchback and conforming, and how they bill. Often a

negative cutter will charge an hourly rate and a per-edit fee. The more edits you have

and the more the conformer has to fish around for the right matchback numbers, the

more expensive it will be to conform your movie.

These are the kinds of “hidden costs” that can be anticipated and budgeted for if you

consult with your lab and negative cutter in pre-production, while you prepare your

budget.