The basic layout of a copy job is to have the camera back, whether film or sensor, parallel to the original. The lights need to be between 30º and 45º from the plane of the original. In this range they light the original but you don’t see reflections of your lights in the original. You can even shoot through glass! The lights need to be far enough from the original to even out the lighting.
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In the example with this article, the lights are about five feet from the center of the original. You need the lights further away from a larger original. The reason for this is that if the distances from the light to the corner of the original and to the center of the original are significantly different you will not be able to even out the light.
The amount of light that makes it to the original goes down as the distance to the original increases. So if the distances to different parts of the original are very different you will not be able to even out the light.