Spot metering can be tricky however, depending on the color value you spot meter. For instance, if you let the camera do the "thinking" and spot meter something black then the whole photo will be overexposed as the camera is trying to make the black grey. U would have to set the camera to underexposed by a couple full stops in that instance. I would go to the local library and see if they have the book titled "Umderstanding Eposure". It's a really basic intro into understanding camera settings, what they do, and what times to use different settings. I have had really good results with point and shoot cameras ans just using the macro setting, flash, and then staying back from the marble a bit and using the optical zoom (not digital zoom), then cropping the photo in an editor of your choice.