Marc,
I guess what is missing is the 'interval range' input. Please see the attached VI and image. Open the VI and make sure the Path control is selecting the image I'm sending, then run the VI. You will notice how the second graph shows the 'grass' look histograph, but the third graph shows a smooth histogram as if it was an 8 bit image (first graph). The only change is the interval range. Check the help file for more information. The files are saved in LabVIEW 6.1 and IMAQ Vision 6.1.
Regards,
Nestor S.
Nestor