Multi-Exposure/EV

[Mumfandc]

Hi.

I did a couple multi-exposure shots, and all of them comprised of two shots on one frame. I followed instructions recommended by a book, and got good exposures by setting the EV value to -1 stop (=ing one "correctly" exposed frame...I think).

However, what's the case for 3 exposures on one frame? I'm thinking -2 but not sure...confused w/the math.

 

[Contra|Brett|]

I think you should go -1.5, not -2

1 exposure = o ev comp
2 exposures = -1 ev comp (half as much light, twice)
3 exposures = -1.5 ev comp (one third as much light, 3 times)

every exposure value is twice as much light as the preceding value.

i.e. ev 4 is twice as much light as ev 3.

 

[Mumfandc]

ah... got it. Thanks!

 

[Contra|Brett|]

no problem