# i lost my notes lux2ev

Discussion in 'Exposure Discussion' started by RalphLambrecht, Jun 10, 2012.

1. ### RalphLambrechtSubscriber

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i lost my notes .does anybody have an equation handy how to convrt lux into ev and visa versa?

2. ### Mahler_oneMember

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Hi Ralph:

From Ben earlier today....Check-out ehow.com. Converting Lux to EV; 5.5L=1 EV

Elliot

3. ### Brian PuccioMember

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Stack Overflow says:

You can also use Wolfram Alpha, which, e.g., confirms the above math by calculating 10 EV to be 2560 lux.

4. ### fdisilvestroMember

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Just remember that those values are for ISO 100, otherwise you have to adjust accordingly.

5. ### RalphLambrechtSubscriber

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is there an equationthat considers film speed?

6. ### Steve SmithMember

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Or call it LV.

Steve.

7. ### RalphLambrechtSubscriber

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i call it luve

8. ### andrew.roosMember

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Based on Brian's equation

lux = (2 ^ ev) * 2.5 * 100 / iso

Where iso is the film speed.

9. ### Chan TranMember

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But if you have an illuminance reading in Lux and want to covert to EV it's a bit more difficult.
Log(Lux / 2.5) / Log(2)=EV for ISO 100

10. ### Mahler_oneMember

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Hmmmm....I think I'll stay with EV values.....:}

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me too!

12. ### VaughnSubscriber

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All you need is luve -- just ask any Beatle...