Question

The exposure index El for a 35 millimeter camera is a measurement of the amount of light that hits the film. It is determined by the equation EI = log2 EI = log2 (6-), where f is the "f-stop" setting on the camera, and t is the exposure time in seconds. a. Suppose the f-stop setting is 16 and the desired exposure time is 4 seconds. What will the resulting exposure index be? The resulting exposure index will be EI = b. Suppose the light meter on a camera indicates an EI of -4, and the desired exposure time is 16 seconds. What should the f-stop setting be? The f-stop setting should be

Answer 1

EI = log2

here we have f=16, and t=4 seconds

162 EI = log2

El = log2 (256

EI = log2 (64)

El = log2 (20)

EI = 6 log, (2)

EI = 6(1)

El = 6

.

.

.

.

.

.

.

now we have EI=-4. and t=16

--4 = log2

$2^{-4}=2^{\log _2\left(\frac{f^2}{16}\right)}$

$2^{-4}=\frac{f^2}{16}$

$\frac{1}{16}=\frac{f^2}{16}$

$\frac{16}{16}=f^2$

1=f?

fº=1

$f=\sqrt{1}$

${\color{Red} f=1}$