Quote - I have also noted that when you add some Poser caracters in the country lane scene the render time will be much slower

That's because when a Poser character is added, "Light through transparency" is turned on (whether you want it or not) so that the eyes and stuff render properly. However this does increase render times by a factor of 3 or more. So unless you really need "Light through transparency" on, I'd suggest ticking it "off" before you render.

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