sometimes messing with the exposure is better than re-rendering a huge render. levels, curves, etc. the more familiar you get with the poser renderer and lighting the less you need to resort to this, however, as youll be able to compensate for just about anything simply by changing lighting, shadow, render settings in poser.

the only photoshop postwork i ever do these days is to paint in some small shadows underneath the figures feet to ground it in the background, because if you toggle the ground plane on with raytraced shadows from several light sources your rendertime skyrockets. god forbid you have complex hair and clothing trans in the scene, then it slows down rediculously.

a little trick i sometimes do for gallery renders is a quick depth of field effect. duplicate your layer with your figure, gaussian blur it. then take a soft eraser and erase all of the areas that should be in focus. mess with the upper layer opacity till you get the look you like. this helps a lot to soften the otherwise too-hard edges of 3D and is a lot easier than calculating depth of field settings in the renderer, IMO.