Klaus J. Neumann 
  
33221(D=0,3171) 
  
  
  
  
[—— St.D. RED 
—# St.D. GREEN 
|--— SLD. BLUE. 
  
grey value 
  
1,5 1,7 1,9 2,1 2,3 2,5 2,7 
exposure time [ms] 
Figure 6. Noise of the sensor as function of integration time, 250 Watt Halogen lamp. 
4 INFLUENCE OF AERIAL FILM TYPE AND FILM PROCESSING 
Color negative film with an orange (compared to the color negative films with a clear base) has to be scanned with 
different parameters for each of the three color channels to ensure true-to-color rendition of the image. Fig. 7 shows the 
gray values vs. density for the three color channels of an AGFA H100 color negative film. It is evident that the curve of 
the red channel differs considerably from those of the green and blue channels. The reason is the orange film base. The 
scan was performed with the same integration time and a 1:1 lookup table for all three channels. The above mentioned 
Kodak step wedge was again used as a test pattern. 
AGFA H100 37,8 °C 3 min 18 sec 
  
—+— mean grey value R 
—-— mean grey value G 
  
  
—a— mean grey value B 
  
mean grey value 
  
  
  
  
  
  
  
  
  
  
Figure 7. Gray value vs. density for AGFA H100 color negative film. Film processing with 
temperature and time mentioned at figure top (compare to Fig. 8). 
  
218 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B1. Amsterdam 2000.