Noise in reflections on non-focused objects (cycles) I have a problem with the reflections of light on the more distant objects (drops) in the scene. As it can be seen, camera is focused on front of the stone. Water splashes which are not focused got a noise on their reflections, which is not looking so good. Is there some method to avoid this?

I use gloss filter (0.5), multiple importance, pro-lighting skies addon, clamp indirect (6).

At 1500 samples my render looks this way:

(I know dry stone in water is not such realistic but it is the next step...)

Render consists of three layers in the such composition:
Multiuple Importance for Environment

I do not know how the pro-lighting skies addon works, but enabling Properties Panel / World / Settings / Multiple Importance and highly increasing the Map Resolution might reduce those noises, assuming the highlights are coming from the sky.

Composited Depth of Field

Instead of the real DOF you might try uing the Filter / Defocus node in the compositor.