Friday, December 25, 2009

Comparing Light and its Modifiers

Light is the essence of photography. To understand light the photographer must be fully conversant with its qualities and behavior. In order to manage a light source, we must first be aware of its presence. Various lighting accessories are reflectors/dishes, softboxes, umbrellas, spot grids/fresnel floods and area lamps. When light falls on a subject it creates a range of tones: Highlights, Mid-tones and Shadows. A photographer needs to know how these can be compared with one another, so that the most appropriate light-shaper can be chosen for a specific situation.


Light from a point light source such as an open flash or the sun have a ‘hard quality’. The shadow created by this type of light are dark with well-defined edges. The shadows created by the sun are dark but not totally because earth’s atmosphere scatters/diffuses some of the light. The smaller the light source, the harder the light appears and larger the light source, the softer the light appears. A normal reflector illuminating a person from around 10m distance will give hard shadows. If you use the same reflector, however, to illuminate a smaller subject at a closer distance - a box of matches, for example, from about 10cm, the shadows will be much softer. Hence, a bare Camera Flash/Strobe creates a much harsher light and very well defined dark shadows compared to a bare Studio Flash/Strobe. A hard light will produce a strong difference between light and shadow.


The light from a Flash can also be diffused, spread or reflected off larger surface areas. Directional light maintains its ‘hard quality’ when reflected off a shiny surface but is scattered in different directions when reflected off a matte surface. This lowers the harshness of the light and the shadows now receive fill light and are better exposed to show detail in them. This light is called soft or diffused light. The shadows are lighter and much soft compared to hard light. The quality of this light is similar to that produced by a window without direct sun. This lighting technique is good for images of people, portraiture, fashion and much still-life photography. Again, the distance from the light source to the subject has an important influence on the size of the semi-shadow and the softness of the light. Increasing the distance between the light source and the subject makes the light harder, while decreasing the distance makes it softer If the light is large enough, the hardness or softness of the light is more or less independent of the subject to light source distance. A wall behind the subject will be illuminated to some degree over the whole area. The core shadow will disappear, being replaced by a well-gradated soft shadow. Surface texture on both the subject and the background becomes softer when a large diffused light source is used. As subject surface texture is evened out, this form of lighting is particularly good at hiding wrinkles in beauty photography. In nature, this perfectly diffused light is produced by a completely overcast sky. The technique is suitable for beauty, people and car photography.


Lighting that is done close to the subject shows that the shoot-thru umbrella has more coverage but no ‘wrap’ to it, while the reflective umbrella has less coverage but more even light. When shooting a portrait, the white umbrella when placed close to the subject creates a center weighted soft 'hot spot' of light ie. the intensity is strong at the center, and fades to the shadow. The skin looks soft with this light. At the same close distance, the silver umbrella gives more wrap and even coverage of light. The skin gives shows an even sparkling effect, which is good for people with great skin. At long distance though, both light produce almost the same effect and difference if any is negligible(even for lighting geeks), although the silver umbrella eats up more power from the light source to give the same amount of light as the white shoot through umbrella.


This technique is very old and a creative way to get the light effect of a spot grid light with just the silver umbrella. You can control the coverage to make the light wrap very tight around the subject. Simply close down the umbrella midway to get the effect. Attach a clamp/clip on the rod of the umbrella to make it stay there. I normally use the 32degree spot grid a lot for fashion work, but if for some reason, i can't find one...we know what to use!


This form of lighting has been used since the Renaissance period, of course, by painters of that era including Rembrandt, Caravggio and Vermeer. The more technical use of the term 'chiaroscuro' is the effect of light modelling where three dimensional volume is suggested by the gradation of light to the shadow - often called "shading". In our image on the left, we deepen the shadows by using a black card to make the shading prominent. In the next image below, we replace the black card with a silver/white reflector to fill in the shadow.

Another placement of the umbrella and reflector for a slightly different look.


  1. Good and informative post about comparing light and its modifiers. Keep blogging and thanks for sharing....

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  2. awesome blog ! Looking forward to seeing the actions when them come out.

  3. this was one of the most didactic articles about basic strobist i've ever seen on the internet (and i've seen a bunch), thanks for that Sid.

    other posts are awesome too.

  4. This is probably the most straight to the point and informative one I have ever read! Thank you!