Quote - On the rendering dialog you can change to preview mode via a drop down. Then you can quickly see the lighting in the scene and once you're satisfied you can change it back.

I use this as well in my workflow to Reality/Luxrender. Just the preview lights will give you a 30 second render to get the gist of your scene, then if you're going the Uber route, bump up the settings to 128 samples and ambient occulsion, etc. A UE2 with a modern processor and a huge scene took my rig around 45 minutes in the worst of cases, which is still quite good compared to Lux. Different beast there, and I've come to expect the long renders (talking 6 hours plus on average) but my oh my, the images are worth it!

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