I'm using Poser 8 and I could have sworn that it was possible to render a movie as image files and set a transparent background by using a format that supports them, such as PNG on the renders. However, I tried to render an image sequence recently and it placed the default ugly grayish brown Poser background on every image.

I'm currently just rendering each frame individually rather than trying movie again, but I could have sworn that rendering with a transparent background on an image sequence was possible right? I'd rather do that too because I wanted to enable motion blur and I can't when rendering each frame individually. Can I fix this or am I doomed to keep doing each frame on its own?

In the Poser  render settings, be sure to select "Black" in the Render Over option.  Then save as PNG

I prefer uncompressed tiff renders, but with motion blur I always render to movie.  i dunno if it would even work with stills.