how can I fix this problem with Vray for Maya 2016, I wan a Smooth Shadow. but all the time look like this…to much noise or grainy…I used Vray Lights “Rectangle Light”

how can I fix this problem with Vray for Maya 2016, I wan a Smooth Shadow. but all the time look like this…to much noise or grainy…I used Vray Lights “Rectangle Light”
