Ok update on the above.
The autosmooth is the culprit.
Somehow it auto smooths the whole mesh on export to 3ds.
I know well about only 3ds Max, not about others like Blender...
I think smoothing by automatic is not good, finally manual is better.
In 3ds Max , smoothing is achieved by the function "Smoothing group from No.1 to No.32".
I set those smoothing groups manually by 1 polygon and the next polygon, ...
At making Cylinder or Sphere, the number of the smoothing group is automatically assined by 3ds Max to curved surfaces,
but I usually remove those numbers once and set new numbers manually to avoid irregular Normals/strange brightness.