Is it possible to render with no background? What Im interested in is a completely blank background like a transparent background in photoshop. Background color is a problem when rendering objects that use trans maps, especially hair. Trying to separate them in photoshop is kinda tedious and doesnt work that well...

You should save the picture in psd-Format in Poser, then the alpha-Channel is preserved. You will have the transparent background in the alpha channel.

But what if you want to have an animation with transparency background?

save a succesion of tiffs in 32 bit with alpha channel. but i think also that if you save an avi with no compression and in 32 bit witrh alpha you'll get the same result.

You can also save the file as a png if exporting to PSP 7, (not sure about any of the others) set the background color for the document window to the color you want to have as the background transparency.

I don't understand when you say; "You will have the transparent background in the alpha channel." I know how to export as a psd or tif and be able to access the alpha channel. What I'm not clear on is how exactly to separate the background in photoshop.

menue "selection -> load selection" and then in "channel" you choose "alpha channel". hit ok. hit delete. deselect (strg-d). now go back to layers-tab and put the background that you want on the lower layer, it'll show through. i guess :) i'm writing this from my memory...