Blotchy noise

[3rddimentia]

I've been working on some translucent leaves. I'm using refractive fog (if that's what it's called) I stopped the noisy render issue I had by turning up the refraction subdivs and turing on interpolation. Interpolation sped up the render dramatically, and softened the image quite a bit. But instead of noise, now I'm getting some blotchy dancing spots. I've been trying things for the past 3 days and I'm not sure which way to go. Here is a link to a 300k avi showing the problem. home.iprimus.com.au/wickergray/blotchy.avi
It's more apparent on the top leaf along the edge of the stalk. Can anyone point me in the right direction please?
refraction settings at the moment are
IOR 1
Glossiness .001
maxdepth 5
subdivs 150
and use interpolation is on
exit color is off

[flipside]

Well, 0.001 for glossy is very low, this will give you very blurred refraction.

If you use interpolation, the quality of your glossies is controlled by the interpolation settings. I think you need to play with this.

But first I would try without interpolation. Do you get a noisy render if you use subdivs=10?

[3rddimentia]

Yes the very low setting for refraction glossiness is working very well for what I need it for.
Thanks I will have a look at interpolation settings.
I have tried it without interpolation and get VERYnoisy renders even when set as high as 50. I haven't tried it at 10 but I'm assuming that this will increase the noise?
I'll give your suggestion a go. Huge thanks.