Kodak Module 9 Optical Sound Processing, Storage of Solutions, Overview, Sound Track Control

Storage of Solutions

Do not use replenishers that have been stored at normal room temperatures 21 to 24°C (70 to 75°F), longer than the times given in Table 9-9. Storage temperatures higher than 24°C (75°F) will decrease the storage life of the solutions. Storage temperatures below 16°C (60°F) can cause some solution constituents to precipitate.

Do not attempt to bring aged replenisher solutions to the formula level. Decomposition products that are formed as the solution stands cannot be eliminated from the solution. These compounds build up to a concentration that can cause adverse photographic effects.

Table 9-9 STORAGE LIFE OF REPLENISHER SOLUTIONS AT 21 TO 24°C (70 TO 75°F)

Replenisher	Floating Cover	Open Tank
Color Developer	2 weeks	1 week
SD-50Ra, SD-51R
Stop SB-14	Indefinite*	8 weeks
Others	8 weeks	8 weeks
	Closed, Full Glass	Open or Partially
	Container	Full Container

*If solution is kept clean.

Discard the remaining few litres of replenisher before fresh replenisher is pumped into the holding tank. Replenisher remaining in the holding tank, even if kept under a close-fitting floating cover, usually has deteriorated to such an extent that it is unsatisfactory for further use.

For best process control, equip the holding tank for the color developer replenisher with a tight-fitting floating cover. The cover will minimize air oxidation of the solution, and absorption of carbon dioxide from the air, which would change the pH. Clearance between the cover and the tank

wall should not be greater than 1⁄ inch (6.4 mm). 4

Polyethylene sheeting of 1⁄ inch (12.7 mm) thickness makes 2

adequate covers in sizes up to 3 feet (1 meter) in diameter. A dust cover, alone, permits air to contact more of the solution surface and allows air oxidation to take place. Dust covers should be used for non-developer solutions to minimize dirt in the replenisher tanks.

OPTICAL SOUND PROCESSING

Overview

The sound track is printed onto KODAK VISION Color Print Film / 2383, KODAK VISION Premier Color Print Film / 2393 and KODAK VISION Color Teleprint Film / 2395 / 3395 from a negative sound original. Only the cyan emulsion layer should be exposed. This can be accomplished by using a KODAK WRATTEN Gelatin Filter 29 in the light beam. (Some "ND" filtration may be necessary for optimization.)

In Process ECP-2E, the developer produces a positive

silver and dye image of the sound track. As with the image areas, the bleach converts the silver image back to silver halide. The silver halide is removed from the film by the fix. The dye track will be a cyan only image after processing. No special sound track equiment is necessary. If a first fixer is still periodically in use on a processor, it may be skipped by threading the film directly from the stop wash into the bleach or bleach accelerator if no sound track development is required.

An overview of dye sound tracks can be found in Dye Sound Tracks: A Laboratory Guide, available from our Entertainment Imaging offices or the Eastman Kodak Company website at http://www.kodak.com/go/motion.

Sound Track Operating Specifications

SMPTE Standards 40-2002 and 41-1999 define the location and dimensions of the sound tracks for 35 mm and 16 mm films respectively.

Sound Track Control

The major control parameters in the production of optical sound tracks are the position of the track on the film, the width of the track, and the unmodulated density of the track. The sound track densities are dependent on processing conditions and on the amount of exposure of the sound track during printing. Unlike redeveloped silver or high magenta sound tracks, the optimum density of cyan dye tracks should be measured in Status A density.

The optimal variable-area sound track density on KODAK VISION Color Print Film / 2383 and KODAK VISION Premier Color Print Film / 2393 is between 2.0 and

2.2(read as Status A density) The blue and green Status A densities should be between 0.2 and 0.4 The filter pack should be adjusted to give the proper green and blue responses. Once a filter pack is found that produces blue and green densities in this range, the red density should be used as the primary quality control parameter. Choose a print density that will provide a good compromise between signal- to-noise ratio and frequency response.

The densities of the sound track negatives required to produce minimum cross-modulation distortion at optimal print densities are determined using recognized cross- modulation test procedures.

Process ECP-2E Specifications 9-27