Agfacontour Professional was (as of 2002 not anymore produced[1]) a special emulsion sheet film which, after exposure and development in the Agfacontour developer, produced direct equidensities.
Agfacontour was introduced in 1970 by Agfa-Gevaert to produce equidensities by a direct, one-developing-step process.
Until then equidensities had to be obtained using one of the following techniques:
Each of these techniques had its drawbacks of which reproducibility and extensive work involvement were undoubtedly the most important ones. Therefore the researchers at Agfa-Gevaert set up a workgroup to develop a film that enables the use of equidensitometry with the following, principal evaluation methods of an information-carrier [2]
The Agfacontour film contained two special emulsions with each different spectral sensitivity.[2]
Although the material exhibited very low sensitivity (long exposures were necessary) the results were very reproducible and second order equidensities were sharp and clear, something that with pseudo-solarization was almost impossible to achieve without special procedures.[3]
The Gamma of the material was very high (approx. above 7.0), power of resolution was 40 lines/mm[2]
Since the introduction of Photo editing software, altering curves into U-curves also produces equidensities.
For the image at the right a darkroom process was used that encompassed the production a serie of equidensities of the negative, enlarged on Agfacontour Professional sheetfilm. Each sheet was then copied onto lith film and developed in lith developer. Each copy was then developed in a chromogenic developer. All colored lith films were then put together in register and a positive print on color paper was made.