Traditionally, continuous lighting was always used in studio situations. However, in more recent years and in the vast majority of studios, electronic flash is now the norm. Tungsten (continuous) light has the advantage of being a little less expensive than flash, but unfortunately the many drawbacks outweigh this.
The main problem with tungsten light is that it generates more heat than light, the colour of the light it produces is very yellow and it gets worse as the bulb ages. This means that you have to use either a tungsten balanced film or a filter on your camera to compensate. For digital users the problem is not so pronounced as the White Balance setting on the camera can be set to the specific colour temperature of the tungsten light. Studio tungsten will be rated as to the colour temperature it produces, and more modern units are fairly close to daylight at around 5000K, enabling you to easily cancel out the colour cast.
However, because of the heat, there is also a very limited range of accessories and mixing tungsten with daylight can be a problem.
Anyone who has spent any time either side of the camera with tungsten light will know all about the heat it produces. This can make your subject very uncomfortable and due to the brightness, causes the iris of the eye to close right down. It is often the case that eyes look more attractive with a larger pupil.
|With bright tungsten light the iris closes right down.||With flash the iris does not react fast enough to be a problem.|
The disadvantage of using a standard on-camera type flashgun is that you can’t see the character of the shadows as you arrange your image.
Studio flash overcomes this problem by using a modelling lamp which should mimic the light produced by the flash tube. This enables you to set up your lighting with the confidence of being able to see what you are going to get! - WYSIWYG - What you see is what you get!
However, various makes of studio flash have modelling lamps which are not always equal. I have always used the Prolinca/ Elinchrom system because of the advantages they give me. Firstly the modelling lamp bulb is exactly in the centre of the flash tube and almost the same size. This means that the modelling light is virtually identical to the flash - WYSIWYG!
Another big plus of this system is the huge range of accessories, the secure accessory fitting and the performance of the flash. The flash duration is very fast, typically over 1/1000th sec. This means that not only will it freeze action, but there are no problems mixing the flash with daylight, and using a fast shutter speed. Recycling times are also very fast, generally less than a second, so I never miss a shot! Big problems can occur if your shutter is faster than the flash!