Image 16

original lighter colour coded

and with an inserted data grid:

(in the middle of tiles, median of raw G-pixels values is given, the bottom value is the tile luminance divided by one candela per square meter). 
# Date/Time    : 2006:06:29 02:37:16
# Resolution   : 1280 x 960 in jpeg (1424x1076 in pgm/16.pgm)
# Focal length :  5.7mm  (35mm equivalent: 39mm)
# CCD width    : 5.32mm
# Exposure time: 0.500 s  (1/2)
# Aperture     : f/2.8
# ISO equiv.   : 200

# Selected image percentils         L=(1.730*0.35*R+1.000*0.65*G+1.570*0.00*B)* 6.64E-4
# %    R     G1    G2    B readings  R        G        B        L / cd/m2
  1   -57   -54   -55   -55        -0.0655  -0.0362  -0.0574  -0.0465
 10   -28   -25   -26   -27        -0.0322  -0.0169  -0.0282  -0.0223
 50     0     0     0     0         0.00     0.00     0.00     0.00  
 90    40    38    38    38         0.0460   0.0252   0.0396   0.0325
 99    79    76    76    75         0.0908   0.0505   0.0782   0.0646
100 15869 15866 15866  3944         18.2     10.5     4.11     13.2  
# flux from 0.654*0.54 sr ( 8.59E-7 sr/4px) is  0.00266 lx ( 0.00490 lx tilewise);
# tilewise luminance  0.00767 cd/m2 with rel. SD  115 % (summing pixels below 15850 and with non-zero green: there is 54.4 % of them)
# Fuji Devignetting: 1 # dark frame dark/42.pgm subtracted from all values
# Red  average=   8.9  minimum= -126  maximum=15869   over 15850:   3 zero: 41.8 %
# GrUp average=   9.2  minimum= -129  maximum=15866   over 15850:   3 zero: 45.6 %
# GrDw average=   8.8  minimum= -134  maximum=15866   over 15850:   4 zero: 45.6 %
# Blue average=   7.3  minimum= -131  maximum= 3944   over 15850:   0 zero: 44.4 %

End of results of "raw2lum" (version 1.22) with parameters:
  -c fuji -fa -d dark/42.pgm -sm100 -nh -nt -i 16.txt -e 16.eps -n 16.ppm -t 118 -s71:76 pgm/16.pgm
Luminance scale / 1 cd/m<sup>2</sup>
Logarithmic luminance scale (the unit is candela per square meter) – intensities of snow illuminance in lux would be obtained by multiplying the numeric value of luminance by 3.6. For asphalt, such a coefficient is between 20 and 40 (or much less, for specular reflection of distant lamps)