EI/ISO values for video cameras
Posted 15 July 2005 - 01:49 AM
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..
Posted 15 July 2005 - 06:36 AM
the UVW 100 is given for F 11 at 2000 lux, wich is about 800 ISO
Posted 15 July 2005 - 06:51 AM
The 637 reference I 've got is assuming an Hyper HAD sensor :
The UVW 100, a Power Had one :
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
Posted 17 July 2005 - 04:36 PM
thanks again for the info.