anned with 
Shows the 
he curve of 
| base. The 
mentioned 
"th 
Klaus J. Neumann 
  
During the test, the same film with the same step wedge, but processed with different temperature and different time, 
was scanned. The influence of film processing on the variation of the characteristics of the curves is clearly visible in 
Fig. 8. 
AGFA H 100 41?C 5min 40 sec 
300 T 
150 + 
  
| |—*— red 
: 7 green 
| | |74— blue 
  
  
mean grey value 
  
100 
  
  
  
  
Figure 8. Gray value vs. density for AGFA H100 color negative film. Film processing with 
temperature and time mentioned at figure top. 
The color balance is usually obtained by the use of individual lookup tables for each color channel. The closer the three 
color density curves of the film are, the less necessity exists to correct color rendition by lookup table manipulation . In 
the case of strong histogram stretching to achieve color balance, the signal noise of the CCD line will be amplified. 
5 CONCLUSIONS 
The major conclusions that can be drawn from the above investigations are: 
An improved radiometric quality during the scanning process can be achieved by reducing gray level noise, e.g. by 
the use of more powerful light sources featuring in particular a large blue component. 
When adjusting the CCD spectral response, care must be taken to ensure maximum coincidence of the 
characteristics of the individual color channels. 
The fine graduation of the integration time permits optimum setting during the scan to obtain the best possible 
analog signal. 
A close contact between the film lab and the digital production site helps ensure that film processing can be adapted 
to the scanning process. Since photography and film processing involve a large number of variables, the best 
possible process can usually only be found by experimentation. It is always useful if a calibrated gray scale is 
provided on the film material so that a reference of the film characteristics is available during scanning to support 
the setting and use of an appropriately tuned lookup table. 
Over- and underexposure should be avoided, if possible, in order to remain within the linear part of the film 
characteristic. 
REFERENCES 
Eastman Kodak Company, 1998. Preliminary data sheet KLI-10203SQM. Microelectronics Technology Division, 
Rochester NY, USA. 
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part Bl. Amsterdam 2000. 219