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EI/ISO values for video cameras


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#1 Daniel Sheehy

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Posted 15 July 2005 - 01:49 AM

hi, I am a lighting camera operator for a production company in Suva (FIJI)

I was wondering if anyone had calculated or knew the equvalent EI or ISO values for either of these two Sony SP Betacam cameras (with a gain setting of 0db):

-DXC 637 with 6.8 x 12 fujinon wide zoom lens
-UVW 100 with x16 zoom lens (I think this one is a cannon lens)

I am aware that there is a way to calculate it, but at the moment my waveform monitor is out of action...

thanks in advance for any info..

daniel
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#2 Laurent Andrieux

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Posted 15 July 2005 - 06:36 AM

the 637 is given for F 8 at 2000 lux that is about 400 ISO
the UVW 100 is given for F 11 at 2000 lux, wich is about 800 ISO
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#3 Laurent Andrieux

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Posted 15 July 2005 - 06:51 AM

Sorry, wanted to edit, but too late...


The 637 reference I 've got is assuming an Hyper HAD sensor :
http://www.scubatech.com/637.htm

The UVW 100, a Power Had one :

http://betacam.palsi...vw100feat.shtml

the rule is : N²/t = E.S/250, where N is the F stop, t the exposure time, E the required lumination (generally 2000 lux for the given carachteristics)

What you can also do if you have no waveform monitor, as a quick guide with a lightmeter :

- have a properly set monitor,
- frame an average scene with no peak of light, nor large dark areas, incident light being the same on the whole set ; no backlight.
- press the momentary auto iris button
- check the given stop by the auto iris system
- measure the incident light of the scene, whatever sensitivity you compute, but set the proper exposure speed
- search while changing the sensitivity setting wich sensitivity gives you the same stop as the camera has given
- a difference of a third of a stop or less is acceptable
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#4 Daniel Sheehy

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Posted 17 July 2005 - 04:36 PM

Yes the sensors are as you described.

thanks again for the info.
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