I forgot writing pertinent information.
POV version :
3.1a.watcom.win32[Pentium II optimized]
and
3.02.watcom.win32[Pentium optimized] ( the results are almost the same
as Version 3.1a )
Machine :
IBM Aptiva
CPU : Pentium MMX 233MHz
Memory : 64 MB
OS : Windows95
Best regards
Masanori Imazu