With film, she takes her clothes off, you look and snap away. She goes away without ever seeing a picture. Great. You didn’t even have to use film. Just peeka boo.

Porta Notes:

The Kodak Professional Portra family of films was originally launched in 1998. Since then, Kodak has made many advances in color negative film technology. The films introduced at Photokina 2006,
the Kodak Professional Portra 160 NC and VC, and the 400 NC and VC films, have been reformulated to improve performance. This paper will describe the new components and their features. These include
emulsion improvements: optimized T-Grain technology, antenna dye sensitization, and improved spectral sensitivity. Chemical improvements are also described: Advanced development accelerators, a new high-efficiency masking coupler, and improved DIR couplers.

Daniel Kennelly received his B.S. degree in Biology
from the Siena College in 1978 and a M.S. in Mathematical
and Applied Statistics from Rochester Institute of Technology
in 1989. Since 1985, he has worked in the Research Labs at
Eastman Kodak Company in Rochester, New York. His work
has been primarily focused on the development of new color
negative film products. He has been the technical designer
for the Portra 160 films since their introduction in 199.. [TDPF_2007_art00004_Daniel-Kennelly]

US 5773208A	it is the most basic goal of photographic technology to provide excellent discrimination depending on exposure or lack of it. [1996] JEFFREY HALL
US 6143486 inventor:(Richard L. Parton)	This invention comprises a silver halide photographic material comprising at least one silver halide emulsion comprising silver halide grains having associated therewith at least two dye layers comprising(a) an inner dye layer adjacent to the silver halide grain and comprising at least one dye that is capable of spectrally sensitizing silver halide and(b) an outer dye layer adjacent to the inner dye layer and comprising at least one dye,wherein the dye layers are held together by non-covalent forces or by in situ bond formation; the outer dye layer adsorbs light at equal or higher energy than the inner dye layer; and the energy emission wavelength of the outer dye layer overlaps with the energy absorption wavelength of the inner dye layer.PARTON
US 6165703	Increasing the absorption cross-section of the emulsion grains should lead to an increased photographic sensitivity. The need is especially great in the green sensitization of the magenta layer of color negative photographic elements.[1998] RICHARD PARTON
US 6,331385	One way to achieve greater light absorption is to increase the amount of spectral sensitizing dye associated with the individual grains beyond monolayer coverage of dye (some proposed approaches are described in the literature, G. R. Bird, Photogr. Sci. Eng., 18, 562 (1974)). One method is to synthesize molecules in which two dye chromophores are covalently connected by a linking group (see U.S. Pat. No. 2,518,731, U.S. Pat. No. 3,976,493, U.S. Pat. No. 3,976,640, U.S. Pat. No. 3,622,316, Kokai Sho 64(1989)91134, and EP 565,074). This approach suffers from the fact that when the two dyes are connected they can interfere with each other’s performance, e.g., not aggregating on or adsorbing to the silver halide grain properly.
US 5607826	ECN structure
US 4810626A	[1986]
US 5049485	The photographic silver halide emulsions can be used and incorporated in photographic elements that are single color elements or multicolor elements. Multicolor elements contain dye image-forming units sensitive to each of the three primary regions of the visible spectrum. Each unit can be comprised of a single emulsion layer or of multiple emulsion layers sensitive to a given region of the spectrum. The layers of the element can be arranged in various orders as known in the art.[1990]DEATON
US 5451492	yellow: DIR couplers perform one or more useful functions including control of contrast or gamma, sharpness enhancement, granularity reduction and color correction via interlayer interimage effects. The latter function is particularly important in modern color photographic materials. For example, DIR couplers are widely used in the blue-sensitive, yellow dye-forming layers of color negative films, not only for improved sharpness (or acutance) but also to reduce development and dye formation in other layers, especially adjacent green light-sensitive, magenta dye-forming layers. This type of interlayer interimage effect can help correct for unwanted absorptions of the yellow dyes in areas of the negative that contain magenta dyes. It also allows a film to be constructed with higher color contrast while maintaining proper neutral contrast. To date, combinations of yellow image dye-forming couplers and DIR couplers have not provided satisfactory interlayer interimage effects.[1994] PAUL MERKEL
EP 057,7191 B1	A color photographic element is disclosed comprising a support bearing at least one photographic silver halide emulsion layer, an image dye-forming coupler, and a coupler (A) capable of forming a compound that is washed out of the photographic element upon processing and capable of releasing a bleach accelerator group, [BARCS:BEGLEY]
US 5272043	solves these problems by providing a photographic element comprising a support bearing at least one photographic silver halide emulsion layer in association with at least one DIR (development inhibitor-releasing) coupler containing a solubilizing group which enables the coupler upon oxidative coupling to form a dye capable of being washed out of the element upon processing and in the coupling position a coupling-off group comprising at least one releasable mobile development-inhibitor moiety[yellow filter dye: BEGLEY][1991]
US 5723280	One critical need for spectral sensitization of color negative and color reversal films is to have a high degree of accurate color reproduction. To do this the film must be sensitized as closely as is possible to the sensitivity of the human eye. Particularly in the red region of the spectrum current, films are mismatched from the human eye, with peak red sensitivity Of the film occurring at wavelengths greater than about 640 nm, while the eye has a peak sensitivity around 610 nm.[1998] LINK

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