Hi guys, finally the blur is ok with me... attached is my last setting.
Now I learn one thing that vfsu is different than my DSLR, I used F/2.8 lens at 200mm and 5 meter object (ISO 100, speed 1/100) but different here in vfsu, number can vary from 0.01
now I have to get used to this ^^

One last question, Stefanq said that he didnt use physical camera setting, so what setting should I used without physical camera On ?
Thank you Chris, TIG, Thom, & Stefan.

Hi guys,
Thanks alot for the reply even I not fully understand it all ^^
I tried Stefanq setting, put down the F number to 0.1 and ISO to 1.0 and finally the blur came out, and only distance 703" is sharp.
However I need extremely blur to the black and blue ball, I tried the F number to 0.01, but all become wash out white.
eventhough I increase the speed to 16,000 to reduce light, it still wash out white. Do you have any advice how to get the blur more ? many thanks.

Hi TIG and Chris Fullmer, thanks for your reply.
I think I already put the unit into inch. and I already put 703 (not just 10) in Overide_focal_dist, but the result are all sharp.
I got 703 from get_camera_distance plugin, on the red ball.
here I attach another screenshot with color and setting, I'm going to make the red ball to be sharp and the other ball become blurry.
Do you have simple samples of your blurred .skp ?
and here also my .skp file in google drive:
https://docs.google.com/open?id=0BxjFhe9IY4QWLWUyYVFKdFNWRHM
many thanks for your help guys.

Hi, I got confused about this.
I try using get_camera_distance but the result aren't DOF
am I missing something ?

here I attach my screen shot
if too small I also upload here:
http://imageshack.us/f/254/bingungdof2.jpg

please advice, thanks alot.

@solo said:

Have you checked for reversed faces yet?

Ah, you right, I flip them and put texture, it suddenly shown the texture, so all this time I use the negative side.
Thank you very much Solo.....

I'm using Sketchup 8.0.3117 and Vray core 1.70

from the pic above,
when I use File - Import - image as texture, the reflection on the mirror is missing.
please help, I can't find any solution on google.
Thank you very much.