Silver halide color photographic material
AssigneeKonica Minolta Photo Imaging, Inc.
InventorKuniaki Uezawa
Life of this patent
Estimating the term…
Abstract
The present invention provides a silver halide color photographic material having a relatively low silver content suitable for digital print, leading to print quality superior in contrast and color reproduction is attained irrespective of camera quality used for picture-taking. The silver halide color photographic material, after having been processed, satisfies the following equation (1) which is calculated for under-exposure, correct exposure and over-exposure and any one of the color-sensitive layers satisfies the following equations (2) and (3) with respect to gradients (γU, γN, γO) for under-exposure, correct exposure and over-exposure. Crm≧1045−log10S×75 (1) 0.92≦γU/γN≦1.05 (2) 0.92≦γO/γN≦1.05 (3)
Claims8
A silver halide color photographic material comprising on a support a red-sensitive layer, a green-sensitive layer and a blue-sensitive layer, wherein after subjected to color processing, the photographic material satisfies equation (1) below with respect to Crm values which are defined as below and calculated for under-exposure, correct exposure and over-exposure;
- the red-sensitive layer, the green-sensitive layer and the blue-sensitive layer each satisfy the following equations (2) and (3) with respect to gradients (γU, γN, γO) for under-exposure, correct exposure and over-exposure;
- Crm≧1045−log10S×75 equation (1)
- wherein S is a nominal speed of the photographic material, and Crm is defined as follows:
- when a Macbeth color chart (having 24 squares) having been photographed with the photographic material using a * camera under a sun light source having a color temperature of 4800° K at each of a correct exposure (N), an under-exposure (U) of being 2 stops down from the correct exposure and an over-exposure (O) of being 2 stops up from the correct exposure and after having been processed, the photographic material is printed on a color print paper with respect to the respective exposures under such an exposure condition that N5 gray of the Macbeth color chart (gray chart of 18% reflectance) gives values of L*=50, a*=0 and b*=0, metric chroma Cab* values are determined for Blue, Green, Red, Yellow, Magenta and Cyan of the color chart at each of the under-exposure, the correct exposure and the over-exposure and the Crm value is a total value of the metric chroma values at the under-exposure condition, correct exposure condition and the over-exposure condition;
- 0.92≦γU/γN≦1.05 equation (2)
- 0.92≦γO/γN≦1.05 equation (3)
- wherein when a density function curve (D-logE) indicating a relationship between exposure and color density is prepared for the photographic material processed, the γU, γN and γO are each determined by the following definition:
- γU:
- a slope (tanθ) of a straight line connecting an exposure point (−0.1−log10S) and an exposure point (0.9−log10S),
- γN:
- a slope (tanθ) of a straight line connecting an exposure point (0.5−log10S) and an exposure point (1.5−log10S),
- γO:
- a slope (tanθ) of a straight line connecting an exposure point (2.0−log10S) and an exposure point (3.0−log10S).
A silver halide color photographic material comprising on a support a red-sensitive layer, a green-sensitive layer and a blue-sensitive layer, wherein after subjected to color photographic processing, the photographic material satisfies the following equation (4) with respect to a quality value QC as defined as below;
- the red-sensitive layer, the green-sensitive layer and the blue-sensitive layer each satisfy the foregoing equations (2) with respect to gradients (γU, γN, γO) at under-exposure, correct exposure and over-exposure,
- QC≧15.982×S−0.378 equation (4)
- wherein S is a nominal speed and preferably from 100 to 800;
- and QC is defined as below;
- when a Macbeth color chart (24 squares) having been photographed with the photographic material using a camera under a light source having a color temperature of 4800° K at an under-exposure of 3 stops-down from normal exposure in which the aperture of the camera is reduced by 3 steps from the normal exposure and after having been processed, the photographic material is exposed to obtain a print under the exposure condition so that N5 gray of the Macbeth color chart (gray chart of 18% reflectance) gives values of L*=50, a*=0 and b*=0 and 18 colors other than gray are subjected to chromaticity measurement, the quality value of QC is calculated according to the following equation (5):
- QC=(Cr+Ch)/2 equation (5)
- wherein Cr and Ch are defined in the following equations (6) and (7):
- Cr=20×log10(Cr0) equation (6)
- Ch=7.0−3×log10(Ch0) equation (7)
- wherein Cr0 represents a ratio of a mean metric chroma value Cab* calculated from chromaticity values of 18 colors of the Macbeth color chart to a mean metric chroma value Cab* calculated from chromaticity values of 18 colors of the print of the Macbeth color chart;
- and when from color vectors of the 18 colors of the Macbeth color chart and the respective color vectors of the print corresponding to the Macbeth color chart, chromaticity fluctuations for the respective colors are represented by an angle between the foregoing color vectors for each of the 18 colors, and a mean value of the chromaticity fluctuations is designated as Ch0.
Dependencies are inferred from the claim text.