I thought it important to mention when using natural light in a backlit scenario glassware can get really tough to hold detail in it. Here is an example where there are three pieces of glassware in each shot. Notice how in the backlit shot the two drinking glasses are totally blown out. There is absolutely no detail in them what so ever. You can try to block light from blowing these out but it can be quite challenging and sometimes it might just be better to move camera or your set so that the light is more from the side.