There’s a lot of myth and misinformation out there about grey cards. They’re often a bit of a pain to use sometimes, too. But they can be one of the most valuable tools photographers have at their disposal when it comes to getting good and consistent exposure. In this video, David Bergman walks us through how to use one.
To understand why a grey card works one needs to understand how a basic camera meter sees. While there are many intelligent exposure modes in cameras today, most still try to balance out the picture to 18% grey. If you shoot against something black it will overexpose it to make it 18% grey. If you shoot against snow, it will try to underexpose it to make it 18% grey.
When you’ve got your camera looking at something that is 18% grey, it is able to put the exposure right where it needs to be, To get a good exposure with a grey card, there are basically two methods you can use. It’s really that simple. Of course, in the real world, constantly pulling out a grey card as the light changes can be a bit of a faff. So, it won’t be useful on every shoot you do, but it will help to ensure you get some kind of exposure consistency where it matters, regardless of how bright or dark your overall scene is.
I often prefer to just go with a handheld light meter when I need that kind of consistency. Specifically, the Sekonic L758DR. But when I do occasionally choose to use a grey card, I use the Lastolite XpoBalance. One side is black, white and 18% grey so you can spot meter on the grey while having a better idea of your scene’s overall contrast. The other side is 18% grey, one stop over and one stop under so that you can get a little more control over exactly how you want to expose.
