Also, something else to try it out is connecting the image node to the ambient color, instead of diffuse, and adjust the ambient value to somewhere between .5 to 1 depending on your scene and lighting.  I know this probably has nothing to do with render being blurry, but in Poser 6 and 5, Daz'a cyclorama renders much darker than in poser4.  Just something else to keep in mind.