Reflection: Whats the difference. Fresnel Tick or Falloff map?

V-Ray V-Ray for 3ds Max General
1

Hi all

In VRayMTL next to reflection there is a check box “Fresnel”. What is the diffrence between ticking this box or applying a falloff map in the reflection texture?

2

for the same IoR, unless you touch up the map curve, none afaik.