So, onto modifiers that make the light harder. Firstly, I must apologise, I told a little white lie earlier. Strictly speaking, no modifier will truly make your light harder, as the light source will stay the same size. What all these modifiers do is narrow down the spread of the light – essentially they restrict where it goes. This may appear to be the same thing, and you’ll often hear photographers talking about “making a light harder”, but in physics terms, the only way to actually make a light harder is to make it smaller. Since these modifiers work by making the light source smaller in relation to the subject, it generally has the same effect though. Apologies for any confusion, I’m just putting that out there for all the physics geeks!.
We can see what I mean by talking about one of the simplest modifiers used to control the spill of light and make it “harder” – a reflector. Most studio or battery flash heads come with, or can be fitted with some sort of reflector – like this zoom one on my Profoto. You may hear them being incorrectly referred to as making the light harder, but all they really do is control where the light falls. You can see this when we zoom this reflector in and out – watch how the spotlight on the back wall changes in size. The quality of light doesn’t really change – the light source is still the same 7” flash tube – but extending the reflector further out limits the fall of the light.
We can take this one step further by using something called grids. A grid is basically a honeycomb pattern held in a disc that you pop onto the front of a light. They come in all shapes and sizes, and are even available for softboxes, where they’re known as egg boxes, and beauty dishes. The size of the holes in the honeycomb pattern determine how tight the beam of light is – you can see here three different ones, a small, medium and large – they’re usually marketed in degrees, which refers to the degree of the beam cast by them. Here you can see the effect of the small, medium, and large grids and the width of light beam they cast.
Grids don’t truly make the light harder, they simply channel it down tighter, allowing you to control where it falls. This can obviously be very useful when you’re building up the light in your image. Essentially, what grids allow you to do is feather the light very precisely – you’ll remember we put a grid on a beauty dish earlier to demonstrate, well here’s one on a softbox. The quality of light is still soft, what the grid has done is keep the light to a narrower channel.
Grids also absorb some light, and this can soon become a problem if your light isn’t very powerful in the first place. This happens because although it may initially appear that what a grid is doing is focusing the light down into a smaller area, what it’s actually doing is blocking large amounts of the light from getting through to your subject. If you’re simply trying to control where light falls, you may be better off with barndoors or flags.
A flag is simply something that you place in front of the light to control where it falls. The simplest version by far is something like this black plastic with velcro on, which I can stick onto the side of a flashgun. Not very high tech, but as you can see it stops the light from spilling out to one side. At the more high end of the scale, you can buy or rent fabric flags, which come in a range of sizes, and fit neatly into the knuckles on flag arms. They do the same job, but look a bit more professional!
Some lights come with fittings called “barndoors”, which are essentially a flag for each side of the light, on a hinge, so they can be swung in and out of the path of the light. You can see here how this tungsten light has had it’s barndoors closed down tight, which stops the light from spilling out all over the place.
To really tighten the beam of light, you can use a snoot. These are essentially tubes that you stick onto the front of a light to spot it right down. This simple fabric one on this flashgun does a decent job, and you can also get them for flash heads where they tend to be bigger and made of metal! On a very basic level, you can use something called Cinefoil, or black wrap. This is aluminium foil that’s painted matt black, and which you can bend into any shape you choose, and shape around lights to limit their spill.
There’s one last modifier that I ought to mention just out of completeness, although they’re quite rare, and that’s a Fresnel, or Frez-nell if you prefer to pronounce it phonetically! These are specifically crafted panes of glass that focus a light into a beam, and give you a small increase in efficiency, as well as creating that “theatre spotlight” look. As I say, they’re not all that common these days, you tend to find them on old fashioned lights like this one, although you can buy them as a modifier to fit on the front of a flash head but they’re VERY expensive. They can be augmented by moving the light inside the housing to broaden or tighten the spread of the beam. Since they can actually focus the light down a bit, they’re probably the only modifier that actually makes a light source truly harder – if you want to create that really crisp “spotlight” look, you’ll need one of these. You rarely come across them though, and when you do, you’re more likely to get into an argument about how best to pronounce them, rather than how to use them!
To recap, most of the modifiers out there on the market that claim to make light harder, aren’t really doing so – they’re just channelling where it falls, and controlling the spread of it. In some cases though, this can have the effect of making the light look harder, particularly if you successfully manage to make your light source smaller in relation to your subject – this though – as we know is often a simple by-product of your direction and distance!