A set of grids is a versatile tool to have in your lighting kit, as they allow you to control very precisely where light falls. This means you can use the same lights, and the same studio to create vastly different looks. The image on the left was taken in the morning, and the image on the right in the afternoon, both in the same studio:
There are 3 things you need to bear in mind when using grids:
Adding a grid consumes some of the light. This took me years (yes, I know, I’m not bright) to finally learn. It’s a bit counter-intuitive, as instinctively focusing the light down feels like it ought to create more light, but grids work by blocking some of the light. So, whilst you’re able to control where it falls better, there’s less of it to play with.
They don’t actually make the light harder, another common misconception. The only thing that makes a light source harder is if it gets smaller in relation to the subject, and since grids simply control where the light falls, this isn’t actually what’s happening. The quality of the light you use will stay the same, there’ll just be slightly less of it hitting your subject, and in a more controlled area.
The main reason for using grids – that you can precisely control the fall of light – is also one of their biggest drawbacks. You’ll need to be very careful about placing lights, and controlling where you subject is, and their use won’t suit everything you shoot. They’re not much use for anything that moves around a lot!
Once you’ve got all that on board, you’re good to go, and being able to control where light falls in your shots allows you to create a range of shadows and highlights, emphasise certain areas of the shot, and transform bland locations into something quite special!
But don’t just take my word for it, let this more lively version of me tell you all about it: