Apparatus, methods and articles for internegative color balancing

• US 4,857,968 A
• Filed: 08/06/1987
• Issued: 08/15/1989
• Est. Priority Date: 08/06/1987
• Status: Expired due to Fees

• Current Assignee: Peterson, Glen
• Original Assignee: Peterson, Glen
• Inventors: Peterson, Glen
• Primary Examiner(s): Hayes, Monroe H.
• Application Number:
  US07/083,232
• Time in Patent Office: 740 Days
• Field of Search: 355/72, 355/74
• US Class Current: 355/72
• CPC Class Codes: G03B 27/73 Controlling exposure by variation of spectral composition, e.g. multicolor printers

Abstract

A section of film forms a gray scale having a series of portions forming steps with progressively changing densities and is supported below an opening in a top wall of an enclosure with an internegative being supported therebelow, the internegative being movable to allow sequential exposure of a series of separate portions thereof, while using different color selected filtrations. The gray scale and the number and relation of the exposure positions are such that the internegative is used to a maximum extent and such that a color balance is readily seen from a visual examination of the developed internegative.

Claims

1. Apparatus for color balancing of internegatives which will be subsequently used to print as positive on color printing paper or film, comprising:

an enclosure including a top wall having a generally rectangular opening therein, a door on said top wall movable from a closed position over said opening to an open position to allow light having a selected filtration to pass through said opening, a gray scale holder for supporting below said opening a section of developed 35 mm color film which forms a gray scale having a series of portions forming steps with densities changing progressively from a certain minimum density to a certain maximum density and with the differences in density from one step to another being such as to produce a uniform tonal difference throughout the full range of steps on a positive test reproduction of the gray scale, and an internegative holder for supporting an internegative below and in close proximity to said section of developed 35 mm color film which forms said gray scale and for movement to allow sequential exposure of a series of selected progressively different filtrations on to separate portions of the internegative, support means in said enclosure for positioning said internegative holder for movement in a certain path relative to said enclosure, and means for controlling movement of said internegative holder to accurately establish a number of predetermined positions of said holder relative to said enclosure such that each exposed portion is isolated from the other exposed portions and while allowing a maximum number of exposures to be made on the internegative, whereby after completion of said exposures the internegative is developed and can be visually observed as a positive on a video color analyzer or on prints made on color paper or film thereby producing a visual examination capability of the most suitable color balance for the internegative.

2. Apparatus as defined in claim 1, wherein said support means is arranged to support the internegative for rectilinear movement in a certain path to expose a series of portions in side-by-side relation.

3. Apparatus as defined in claim 2, wherein said support means so support said internegative holder that the internegative is movable rectilinearly for sequential exposure of one series of portions along one-half of the internegative and after which the internegative is again movable rectilinearly for sequential exposures of a series of portions along the other half thereof.

4. Apparatus as defined in claim 1, wherein said predetermined positions of said holder are such that spaces are provided between exposed portions of the internegative for application of filtration value indicia to the internegative after development thereof.

5. Apparatus as defined in claim 1, including means on said enclosure for supporting a plan sheet having indicia thereon corresponding to said exposed portions and so arranged as to facilitate application thereto of indicia of color filtration values used in the sequential exposures.

6. Apparatus as defined in claim 5, wherein said indicia on said plan sheet represent the positions of the exposed portions and are in the same positional relationship and orientation as the exposed portions.

7. Apparatus as defined in claim 1, wherein said support means so support said internegative holder that the internegative is movable rectilinearly for sequential exposure of one series of portions along one-half of the internegative and wherein the internegative is thereafter manually rotatable relative to said holder with said holder then being again movable rectilinearly for sequential exposures of a series of portions along the other half of said internegative.

8. Apparatus as defined in claim 7, including means on said enclosure for supporting a plan sheet for application thereto of indicia of color filtration values used in the sequential exposures, wherein said plan sheet has indicia thereon representing the positions of the exposed portions and in the same positional relationship and orientation as the exposed portions.