Quality of clouds is already 2, but it seems it isn't enough...
(http://img218.imageshack.us/img218/6441/goodclouds.th.png) (http://img218.imageshack.us/i/goodclouds.png/)
Erwan
I assume you're referring to the noise on the horizon. This is most likely due to needing more atmosphere samples, not cloud quality/samples.
- Oshyan
If I have a lot of noise in the image, I bump up the atmosphere samples to 128 (max). 96 works well also. Decreasing the haze density may help. I have very rarely had to use more than 1 in the cloud settings. 128 atmosphere samples increases the render time, but not too significantly, even on my Pentium 4.
Atmosphere samples increased to 32 instead of 16, clouds quality back to 1. 5h48 to render.
(http://img403.imageshack.us/img403/6441/goodclouds.th.png) (http://img403.imageshack.us/img403/6441/goodclouds.png)
Erwan
Much better! try 64 and bam! Perfection...