I've been studying Renderman lately. According to Stewer (in a post from RDNA I believe) says there's several similarities with P5/P6 material room and Renderman's shader systems. In my own research so far, the Firefly renderer APPEARS to mimic Renderman's capabilities in an, albeit "budget" interpretation. An interesting tidbit in the book I'm reading (Renderman For Beginners, published 2005) says that it's faster when: (a) texture maps are square (the Daz maps I have are rectangular; you can "square" them in Photoshop with no apparent effect since upper left corner is 0,0 and lower right corner is 1,1 and the UV values are adjusted to fit properly - don't forget to use pixel values that are powers of 2 - 256x256, 512x512, etc.) (b) Minimum Shading Rate is a higher value (for drafts). I would tend to agree with face_off, in that you may notice little difference when using a shading rate less than 0.5, but I am in the early phases of running the Firefly renderer through its paces. I imagine that setting Min Shade Rate to zero would take forever, especially if you're using reflection / refraction et al. (c) Using stochastic sampling, which of course Poser does not offer. I have learned a great deal about post filters to soften / sharpen images. I particularly like using Gaussian blur at 2x2 pixel samples - looks more like film. Now what does this have to do with your spot node problem? Absolutely nothing. I just love the sound of my own voice and the fact that Poser is so deep that there is always something new to learn.