A new method of preparing the solution of spectral sensitizing dye is introduced It is simple and convenient It can protect the environment against pollution, and improve the preserving properties of the emulsion Its application was carried out in the preparation of the negative color fil

Studying hasbeen done in the negative color film.

Like color films,the picture image formed on dye type black and white film is composed purely of dyes resulted from the coupling reaction of color couplers with conventional color developing agent,thus this kind of films can be easily processed in normal photo laboratories anywhere.

This paper presents a review on the recent advancements of dye-releasing compounds used in color film for instant photography , and outlines their structure and classification.

Recent development on the research of yellow, magenta, cyan and functional couplers and their use in color films are reviewed.

This paper presents an outline of different approaches to improve the image granularity of color negative films, e.

This paper presents a summary of modern techniques used for improving the color rendering quality of color negative film, namely: improvement of spectral sensitivity of photographic emulsion layers, research and use of principal couplers together with functional couplers e.

The new preparation technology of silver halide microcrystals in high speed color negative film in recent years is reviewed, and the effect of the structure of silver halide microcrystals on their photographic properties is discussed.

Under other similar conditions,hi-active cyan color couplers can raise the sensitivity of redsensitive emulsion layer of color negative film by approximately 30%,and augment at the same tlme the contrast.

Yellow filtering layer is an important component of color negative film for ensuring a real color reproduction and improving the image sharpness.

Digital system for coloured pictures of oral restoration;