Lights: Power & Distance

[Tareq]

Hey,

I have a question: let's say you have a light head of power say 1200 or 1000Ws, and say you use a softbox 100x100", what will be the difference or which one do you prefer? to place the light closer to the model and lower the power to say 1/16 or 1/32 of the full power or placing the light far distance from the model and using 1/2 or full power?

and will the size of the modifier will affect on the power and the distance? if yes, what is the ultimate power and distance to use or to be in safe side? i am talking about normal portraits lighting and not high-key or low-key, but both can be included if so.

[Wilt]

'It all depends' upon what you are trying to achieve.

A closer source is a larger source, so it casts softer shadow edges, compared to a farther source. A closer source falls off in intensity faster than a farther source, so contrastiness of lighting (ratio of shadow area vs. lit area) is greater with the closer source. A larger source falls off more slowly than a pinpoint light source, which follows the Inverse Square rule of fall-off.

[Tareq]

'It all depends' upon what you are trying to achieve.

A closer source is a larger source, so it casts softer shadow edges, compared to a farther source. A closer source falls off in intensity faster than a farther source, so contrastiness of lighting (ratio of shadow area vs. lit area) is greater with the closer source. A larger source falls off more slowly than a pinpoint light source, which follows the Inverse Square rule of fall-off.

Great, thank you very much for this so helpful worthy information, your clarify what i was asking about.

Thank you again