Umbrellas with a reflective inside are used by photographers as a diffusion device when employing artificial lighting, and as a glare shield and shade, most often in portrait situations.[19] Some umbrellas are shoot-through umbrellas, meaning the light goes through the umbrella and is diffused, rather than reflecting off the inside of the umbrella[20]. Photographic umbrellas, like all umbrellas, tend to catch the wind, so any umbrella on a lightstand has to be well secured, especially when used outdoors, lest a breeze topple it, possibly destroying the umbrella and/or other equipment on the lightsand.