Best method to preview DOF in 3D ?

[bernhard]

What is your best known method to preview the DOF in 3D.. especially when animated...
do you just prefer to make a quick and fast render to see the behavior and the animation of the DOF ?

curious about all your thoughts !

[Neilg]

You can do a viewport preview with max cameras. it used to work with the standard kind, but now you need to set it to depth of field (mental ray) to get a viewport preview. enabled or not doesn't make a difference to the final vray render.
using tools - preview - grab viewport keeps the dof set up if you turned the preview on to check it if the focus shifts and the timing of it.