If u dont have enough time to render to reduce the noise, u can try this to fix.
Neat Image is an image filter to reduce noise and grain in photographic images produced by digital cameras and scanners.
Neat Image is indispensable in low-light (indoors, night, no-flash, astro) and high-speed (sport, action, children) photography, as well as in raytracing CG.
Neat Image provides the most accurate noise reduction currently available
Neat Image efficiently reduces noise of the following types:
- high ISO noise in digital camera shots
- film grain in scanned film and prints
- JPEG artifacts and more
Neat Image is currently available as:
standalone application (Windows, Mac OSX or Linux)
plug-in for Photoshop (Windows or Mac OSX)
plug-in for Aperture (Mac OSX)
custom bundles of above versions
I'm interested in this software, which I think would be very useful in rendering.