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Diffusing Light


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#1 Deji Joseph

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Posted 07 May 2011 - 07:10 AM

So far the only ways i know how to create a soft source of light are using a soft box, an LED array or a reflector. Recently i read you can use scrim as well, but from experience i believe it only reduces the intensity of the light source. Am I wrong and are there any other methods?
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#2 John Holland

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Posted 07 May 2011 - 10:47 AM

A big poly board a card any thing white you can bounce a lamp off
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#3 Stuart Brereton

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Posted 07 May 2011 - 11:26 AM

Scrims only reduce the intensity of the light. To make a light softer, you have to increase its size, relative to the subject. You can do this by moving the lamp closer to the subject (you may then have reduce its intensity), or you can bounce it, or diffuse it or both. When you do this, the bounce board, or the diffusion frame becomes the source for the purposes of the quality of light. So if you have a 4' x 4' diffusion frame, and your lamp is filling all its area, then your source is effectively 4'x4'.
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#4 Matt Dennie

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Posted 08 May 2011 - 09:21 PM

I think I have a relevant enough question to post it here.

When you diffuse a hard light, about how much of a decrease in luminance do you typically see? I usually factor about 1.5 stops for a shoot through or bounce.
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#5 Stuart Brereton

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Posted 08 May 2011 - 10:13 PM

There's no hard and fast rule, as it depends what you use to diffuse the light. Something light, like Hampshire Frost, or Brushed Silk, could be as little as 1/3 stop. 250 & 216 are slightly under a stop and slightly over a stop, respectively.
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#6 Stuart Brereton

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Posted 09 May 2011 - 06:12 PM

Just had a look around on the LEE filter website. They list the appropriate amount of exposure compensation for each of their diffusions on the details page for each product.
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