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Help to get Dynamic Range and Clipping point


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#1 Thomas Smith

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Posted 18 July 2007 - 10:25 PM

Where can i find information about how can i get the dynamic range from a particular camera like HVX200 or what test should i do to get it.
I bought a Sekonic L-758Cine and i don´t know how to get the clipping points (-,+)and dynamic range(-,+) values (EV), to have the sensibilty of a camera. I like to know this not only to program the Light meter but to know how it´s done.

I should know this, but...
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#2 Chris Keth

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Posted 18 July 2007 - 11:13 PM

Where can i find information about how can i get the dynamic range from a particular camera like HVX200 or what test should i do to get it.
I bought a Sekonic L-758Cine and i don´t know how to get the clipping points (-,+)and dynamic range(-,+) values (EV), to have the sensibilty of a camera. I like to know this not only to program the Light meter but to know how it´s done.

I should know this, but...


Evenly light a grayscale, one of the ones with 21 or 24 shades from white to velvet black. Shoot it so that your 50 IRE falls on the middle chip. Use a spotmeter to record the exposure readings of every single chip on the chart, making sure to record which one was your camera's middle grey.

Import this footage into an editing program and find the first chip that is totally black and totally white. That is your full dynamic range and this info, along with knowing your camera's middle grey chip, will tell you an x-stops over y-stops under range for the camera.

You should be careful doing this though. Video tends to do strange things. Even when I have figured this out in the past, the dynamic range seems to change slightly depending on gain settings and even iris settings.

Edited by Chris Keth, 18 July 2007 - 11:14 PM.

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#3 Thomas Smith

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Posted 18 July 2007 - 11:38 PM

I´ll try this, Thank you Chris
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#4 Chris Keth

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Posted 18 July 2007 - 11:40 PM

I´ll try this, Thank you Chris


I forgot one little thing. You can do this without the step of going into a computer program if you have a reliable waveform monitor that you can read IRE values off of.
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