Renderelements: mix of 8bit and 32bit output

Hi,
I am rendering an animation with renderlements and an output in 32bit hdr files.
For Renderelements like Material ID i only need a 8 bit output. So far I am converting the 32bit MaterialID data to 8 bit after rendering.
Is there a way to make the conversion during rendertime?

I am drowning in data already! and this makes it even more bothersome…

Thanks

Hi Dirk.

U can do it with different render layers.
one for the 32bit without material ID - highres render..
one with layer override in 8bit, no lights, no GI, etc.

cheers