Which pixel filter is best for outdoor scenes?

Brycescaper

I've traditionally used Gaussian which is what I have always used in Bryce as it was the default, as it is in Daz|Studio. Is there a better one that will let the shaded areas less grainy (I typically render 20000 seconds, just under 3 hrs, render quality 1000+ with spectral rendering turned on- BTW, does this make a difference in rendering quality?) I have a customized PC, 32GB RAM, Nvidia 2080 GTX 8GB graphics card and Intel i5 processor. Thanks for any input you can provide.

Brycescaper

Compaion question: Does the radius of the pixel filter make any difference? Default is 1.5, I set mine at .25. Any input on that as well is appreciated. Thanks :)

 

elFletch

the filtering will only really help with smoothing out edges and areas of high contrast. Noise in shadows simply requires time.