Whilst I agree that lighting plays a large part in the renders you've mentioned, Andrew, I think there are other things at play, as well. TO me, it looks as though each of the figures was rendered separately and then placed with a less distinct background. This gives the figures a relative clarity against their background which may not appear so readily if the were against something render in the same settings as a background (if that makes any sense). The poses are against a non-descript paint-spattered backrgound, with no depth or real resolution to it; Ashley is kept bright by her lights, but the coastal backgroud behind her is dull and faded; and the shoes, whilst against a rendered background, are also much brighter than the non-product image. Also, in the case of the shoes, and extra light has been added to give it further lift and definition - the backlight. This tends to be a high intensity, non-shadow light pointing straight at the camera from behind the subject, and is what causes that sharp white line of definition on the edges of an item.

Clarity of render isn't just about textures, or lighting the whole scene well. It can also be about lighting a scene selectively, os that the elements you want the eye to focus on stand out from the rest.

jonthecelt