Our goal as photographers is to present our subjects in their best light, or in artistically interesting light at least. That’s where modifiers come in. Most modifiers are not something you walk around with casually, but thats not entirely true. A modifier can be a wall that you use to bounce light. Modifiers are, at their simplest, anything that comes between the light source and your subject, so filters, gels, grids, reflectors, walls, umbrellas, soft boxes, snoots, beauty dishes and so on are all modifiers and change how your lighting falls on your subject, and the resulting hotspots and shadows.
So what’s wrong with a bare flash? First of all, the flash is a tiny little light source. From this tiny point of light the shadows cast will be hard edged and very contrasty, meaning the difference between the lit and shadowed areas will be extreme, approaching 100% lit vs 0% lit (white vs black). When you are outside on a perfectly clear day the sun is just such a light. Find a shadow, you will see just how hard edged that shadow is. Then on an overcast day find that shadow, note how fuzzy the shadow is, if even there is a shadow. This is the difference between direct light and modified light. Generally though, we don’t want to fully eliminate shadows, but we do want to reduce the difference between the lit and unlit areas to a range our camera can manage. But the real issue is the harsh shadows, they accentuate the very minor flaws in skin, every wrinkle, ever pore.
So, the different major kinds of modifiers, what are they?
Softboxes – A softbox creates a very large light source by illuminating a translucent surface, such as thin white cloth. This is usually coupled with a reflector which collects and directs all the photons from your flash to that white cloth for maximum efficiency. The result is a large lighting surface as your source so that light hits your subject from a wide range of angles reducing shadows. These devices are often collapsible like an umbrella making them mobile.
Beauty Dish – This is a circular thing that looks like a bowl. Dead center of this bowl is a reflector to block the direct light from the flash. The light from this kind of device is perfectly uniform. Beauty dishes are generally solid metal objects so they do not travel well. There are collapsible models but they are pricey and due to the mechanisms not perfectly uniform in their lighting, but they are still very good to have. The mission of the beauty dish is uniform lighting with no harsh hot spot from the direct light of the flash. These are typically only used with studio style strobes though camera mounted flash units can be adapted for them.
Shoot thru umbrellas – A Shoot Thru Umbrella is the cheapest, simplest modifier. It is exactly as you might think, a translucent, usually white, umbrella which turns your small flash unit into a large light surface. There are only a couple of immediate drawbacks to these. A lot of light energy will not make it through the translucent surface. This is due to absorption caused by the material used. Also, light is reflected back toward the light source, which either means you lose it (if outside) or it will be reflected from all over the room, which might create new problems.
Reflective Umbrellas – Also a very inexpensive option these devices let you spread the light source out and send it toward your subject with minimal power loss. The shadows these create on your subject will be harsh due to the directional nature of the device.
Collapsible reflectors – These are used, usually with a helper, to bounce light onto the subject. You can use them with flashes, sunlight, or room lighting. They reflect light, where you get that light is up to you.
Grids – There are tiny grids that mount directly to your flash, and there are grids that mount to your soft box or reflector. Their goal is to reduce that soft box effect a bit. They come in varying degrees of control, which ends up meaning they help fill a gap between full soft box and pure reflector. It is an artistic element to help you control the shadows. Also note, adding the grid reduces overall light output, so you might need to increase power after adding the grid.
Two notes on reflective devices…
First, you have to choose between foil type reflectors and diffuse surface reflectors. The foil style is highly efficient but you will find the light on your subject has a very subtle water reflection kind of look to it. This is also referred to as specular. The light from this surface is pretty harsh and unforgiving, also called contrasty. The diffuse surface is less efficient but evenly distributes the light better.
Second, is the color of this surface. You will see a lot of reflectors that have some form of a gold surface. These have the effect of warming up the subject. This can be overdone, and some reflectors are made to be something like 50% gold, they have alternating lines of gold and white to reduce the warming effect. This is an artistic choice, nothing more. Typically you only find this in the collapsible reflectors as opposed to the umbrellas or other light stand mounted devices.
So, now that we have some devices in mind, what do they do to your pictures?
I will add some pics soon, to illustrate the differences. As with all the articles, and this site in general, it is a work in progress. For now though, know that modifiers, other than using a wall to bounce light from your camera mounted flash, takes you from a casual amateur to a semi pro level, as they take a great deal more effort, cost, and thought to use. They add a layer of complexity to your photography but also open up a world of options. If your interest is wildlife or landscapes, modifiers are of no interest to you. Product, portrait, and other posed / static situations are generally where you find this kind of thing.