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Reflected Light Readings


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#1 Stephen Whitehead

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Posted 07 May 2007 - 09:02 PM

Hey, this is just a simple question of semantics. A reflected light reading is taken from a spot meter right? The reason I ask is just in regards to the kodak exposure examples which are given in reflected light readings. On the 5212 example the white sheets on the bed are listed as +3.3 stops. Does this take into consideration the inherent white tone of the sheets, or is this merely the intensity of light hitting that surface?

Check it out for yourself: http://kodak.com/US/...g....12.6&lc=en

Cheers,

Steve
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#2 Chris Keth

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Posted 07 May 2007 - 09:39 PM

Hey, this is just a simple question of semantics. A reflected light reading is taken from a spot meter right? The reason I ask is just in regards to the kodak exposure examples which are given in reflected light readings. On the 5212 example the white sheets on the bed are listed as +3.3 stops. Does this take into consideration the inherent white tone of the sheets, or is this merely the intensity of light hitting that surface?

Check it out for yourself: http://kodak.com/US/...g....12.6&lc=en

Cheers,

Steve


They're done with a calibrated spotmeter. It's the simplest and most helpful reading they could give you since you don't have to know anything about the surface being lit. If they gave you an incident light reading for specific areas, you would technically have to know the reflectance of that surface to have useful information.
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#3 Stephen Whitehead

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Posted 07 May 2007 - 09:46 PM

They're done with a calibrated spotmeter. It's the simplest and most helpful reading they could give you since you don't have to know anything about the surface being lit. If they gave you an incident light reading for specific areas, you would technically have to know the reflectance of that surface to have useful information.


So then if you put a grey card onto the same spot where they took the reading of the white bed sheet, the reading would be a few stops lower?
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#4 Jake Kerber

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Posted 08 May 2007 - 10:51 AM

The Kodak photo lists a taking stop of T2.8, so all of those meter readings are in reference to that stop. And a light meter is calibrated to give you correct exposure of an 18% middle grey card, so readings need to be interpreted as such. For instance, if you take a reading of the white bedsheet and the meter says F11, but you know that the zone that you want that sheet to fall in is about 4 stops up the scale (zone iX/white), you would set your stop at T2.8 and know the bedsheet will look white. Of course, when using a spot meter you are inevitably going to read the entire scene before you roll and make sure everything in the frame is reading where you want it--face of subject, shadow areas, back wall, window with view to the outside, white bedsheet, etc.

-Michael Jacob Kerber
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