DOF question - Blur Quality

[Streetwise]

When using DOF, blur quality is pretty bad sometimes (very pixelated). How do I improve upon it? Most noticeable against light backgrounds. Click to enlarge.

[Morbid Angel]

its not pixelation, its low sampling. Increase your dmc max subdivs and it should resolve the noise.

[Streetwise]

its not pixelation, its low sampling. Increase your dmc max subdivs and it should resolve the noise.

Perfect! Thank you!!!

[^Lele^]

On top of what's been suggested, you may need to "pad" the Min AA as well: often a 2 or 3 min subdivs will help find and clean defocused details better, without adding much to rendertime.
Also, if max AA was already high enough, try lowering the noise threshold, to make sure V-Ray reaches closer to max AA.
A sampleRate Render Element will let you know which route you should take.