Softboxes and umbellas fit on to studio lights, and their main function is to make the light larger. The larger a light is, the softer the light produced by it will be. This article should help you to decide whether to buy a softbox or an umbrella, and it also explains the different types available.
Softbox or umbrella?
Before I even try to answer that question, you need to know that there are 2 different types of umbrella - reflective and shoot-through.
Shoot-through umbrellas fit between the lamp and the subject, the light passes trough the umbrella and is diffused and enlarged in the process. To get a really soft, wraparound effect, the umbrella is normally placed very, very close to the subject. The disadvantage of shoot-throughs is that some light is always reflectd from the rear of the umbrella and this can cause flare, degrading the quality of the image.
Reflective umbrellas work in the opposite way - the lamp is positioned facing away from the subject, it shoots into the umbrella and the light is then reflected towards the subject. Because of this the source of the light (the umbrella itself) is much further from the subject and so the light is far less diffused and the shadows are harsher.
So in summary, use a shoot through umbrella if you want the softest light possible, use a reflective umbrella if you want the light to be more directional and more controlled but not as soft.
Reflective umbrellas are available in a choice of finishes.
- White gives the softest light
- Silver gives a harsher, more specular light
- Gold (or any other tint) produces a coloured light, which used to be fairly popular when everyone shot on film - but today, most people shoot on digital and it's easy to adjust the colours on the computer.
A softbox is basically a very large reflector, normally with a reflective (silvered or white) surface inside. It produces the same sort of light quality as a shoot through umbrella except that because it pushes all the light forwards, none can spill back towards the camera.
There is a sheet of tensioned white plastic on the front of the softbox, this diffuses and softens the light. Most softboxes also have a second sheet of plastic, between the lamp and the front of the softbox, which diffuses the light even more.
So which is better?
In terms of diffusion effect, there is little to choose between a shoot-through umbrella and a softbox of the same size.
Softboxes are more expensive and bulky than umbrellas, and this is a big snag for some people. Many can be taken apart and reassembled when needed, but this is often a fiddly and time-consuming job - and the cheaper ones are often so badly made that they won't stand too much handling.
Softboxes do have a couple of advantages over umbrellas though, they are more efficient in their use of light because all of it is directed towards the subject, unlike shoot-through umbrellas which direct about 40% of it backwards. There is another difference too; all light sources cause reflections of themselves in reflective surfaces, and so the eyes of your subject will show reflections (catchlights) in the shape of either a round umbrella or a square (or rectangular) softbox. There are a few softboxes that have a round or octagonal shape, and square ones can be 'made round' by masking the front surface if required. The round reflectiosn from an umbrella or a round softbox normally look more natural, but this is a matter of personal preference.
Not all softboxes are created equal!
The design is simple enough but some do a far better job of creating soft, wraparound lighting than others. Some brands (Chimera is probably one of the most widely used by pro photographers) are available with a choice of either white or silvered interiors. The silvered interiors are more efficient in that they reflect more light but the light is slightly harsher and less diffused than those with white interiors.
The better makes are usually fitted with both an effective diffusion panel on the front and with a second (and sometimes a third) diffuser inside, fitted between the light and the front panel. The cheaper makes often have far less effective diffusion and this can creat hotspots (uneven lighting).
Softbox (or umbrella) size
Size is very important. Most studios use a range of sizes for a range of different applications but if your budget and space are limited you may need to make do with just one or two - so which should you get?
Get the biggest one you can. If you want the light to be really soft, place it as close to your subject as you can. If the want the light to be harsher, simply move it further away. Moving a light further away makes it smaller in effective terms, so the light becomes harsher - so you can make a big light source give the effect of a smaller one, but you can't do it the other way round.
This is a very small extract from my tutorial about studio lighting and equipment. I hope it helps you to make your choice. Please be sure to let other Ebay users know whether this short article has helped you by voting. The more votes it gets, the more visible the guide becomes and the more people will benefit from it.