Another EV question

[steveo_mcg]

Right I've been trying to work this out for a bit now:

If I know the EV, ISO and Aperture I want to use how do I calculate the shutter speed? I'm thinking of a formula or process rather than a crib sheet.

 

[wickerman]

I'd have a read here it explains it all better than I could http://www.scantips.com/lights/fstop.html

 

[steveo_mcg]

Mathematically, EV = Log2 (f²/T)

Cool thanks.

Now my maths breaks down. Because I can't get t from the above when I know the rest.

sudo edit: AHAA. t=LOG2(f²)/ev! Thanks
Nope It doesn't...

 

[wickerman]

T=f^2(1/2^EV)

 

[steveo_mcg]

Your mastery of the force is vastly superior to my own!

I could never get my head around logarithm's which I presume is what (1/2^EV) is dealing with?

 

[wickerman]

I could never get my head around logarithm's which I presume is what (1/2^EV) is dealing with?

It's easier to convert the equation to its exponential form...

log^a = x

is equivalent to:

a^x = y

 

[steveo_mcg]

I need to go do some remedial mathematics...

Thanks though David.

 

[Andysnap]

Help me....
my......
brain.......
is.......
melting......

 

[ChrisR]

Beginning to see why crib sheets are a good idea... solving those equations on the fly on a shoot would be a hundred miles beyond tricky!

 

[steveo_mcg]

Yeah I have another idea to try and slim line this and the lack of a simple zone system chart for my meter.