You can also look into Pixel Accuracy, sometimes that affects the blotchiness. Another option I have used is to group everything together except the glass or transparent objects. Group those objects in their own group. Save the scene, then save it under a different name. Go to the original scene and turn the visibility off for the transparent group. Turn off the transparency options for GI and render it, it should be much faster and easier to control the blotchiness. Save that image. Now, in the other scene, make the other group not visible. You really dont even need GI at this point, take the image from before and use it as a backdrop. Then render. In your scene this might work. But in some scenes, the reflections that you want on the glass would be gone. That is where options such as unseen by camera but still seen in reflections helps, but Carrara lacks that option at the moment. The only time I use transparency with GI is when I need some caustics from the transparent object, otherwise I dont use it, if I can get away with it. Either way, if you want to troubleshoot the blotchiness, I would first make the transparent objects not visible. Then render. You might have a very clean image at this point. If not I would adjust the settings without the transparent objects to get it clean. Once clean without the transparent objects, you have found the minimum settings. Once you add the transparent objects back in and checked light through transparency you might have some more blotchiness, just keep at it. I have found that scenes with transparency can take forever to troubleshoot until you establish the minimum quality settings needed without transparency as a baseline. From there it is often easier. Another thing to consider. It may not apply to this scene, but for interior shots I have had much better luck by using a photon emitter as opposed to a real light. A photon emitter is just an object that has a value or color in the glow channel. Most of the time you will have to use the multipy option with a color. Say pure white with the 0-1000 scale. Doing it this way I have found that blotchiness is less of a problem than relying on a bulb, distant or even spotlight. You also get very soft shadows this way. I will usually place the object outside a window, then it will cast "photons" or light into the scene. The GI (photon mapping) handles the bounced light after this point. Finally, often times ambient occlusion is enough to sell a shot, especially a product shot. The SkyLight option as well is often enough. But when I need full blown GI, personally, I have had better luck using a photon emitter. It really depends if you have the time or not, especially if it is for a client. In a production environment, GI is often too slow, which is why it is generally faked, with Ambient Occlusion and good texturing. Every scene is different though. HTH Donnie