Lux and F-stop ??

Hi all,

I was speaking to a BBC NHU cameraman last night and he was saying he might have to retire his ARRI's next year due to the onslaught of digital..

We were dicussing the finer points of both when he mentioned low light. I was none the wiser when it came down to comparisons.

Does anyone know these comparisons please ??

1Lux = ?

2Lux = ?

3Lux = ?

etc..etc.

Cheers all,

Dive safe

DeanB

Lux is a unit of brightness. 1Lux is defined as the amount of light(intensity) you have 1 meter from 1 candle. 2 lux would be 2x as bright = the light you have at 1 meter from 2 candles.

The non-metric US unit is a footcandle which is the amount of light you have 1 foot from 1 candle.

Neither have anything to do with f-stops

Hi Will,

Cheers for the Info..

Dive safe

DeanB

And worse yet the ratings are only comparable within one brand. What Canon considers a 5 lux rating and what Sony does are two different beasts on acceptable video at that lux value. One brand may have a lower lux rating but will still produce worse video than a camera of a higher lux rating at the same values. The fstop is the ratio between the focal length of the lens vs the maximum apperature the iris can open. IE f2 the iris can open to a diameter distance half the focal length.