The Backlighting feature in Arnold 4 was great for creating thin natural materials like Leafs, Gras, etc. I cannot find something similar in the new Arnold 5 Standard Surface Shader.
This has now been combined with the SSS settings. If you turn on Thin Walled in the geometry section, the SSS behaves as backlighting.
There is some documentation on this topic:
its not working , my Arnold version is Arnold 5.0.1.0 and tried the thin walled and sub surface option instate of back lighting it changed my object color . @Zenopelgrims
@Sanjiv Talukdar yeah of course you need to use the same color for both diffuse and sss color slots.