The Three Elements of Exposure Understanding f/stop, shutter speed, and ISO.

The Three Elements of Exposure

Understanding f/stop, shutter speed, and ISO

What is exposure?

• Definition 1: the amount of light it takes to produce a printable image on the negative (film)

• Definition 2: the actual taking of the photo

Understanding exposure

ISO

Aperture (f/stop)

Shutter speed Exposure

Negative and Positive

Exposure Factor 1: ISO

ISO

Aperture(f/stop) Shutter speed

Exposure Factor 1: ISO

• International Standard Organization

• Measures film speed

• What is film speed?

Film speed is not…

Film speed is….

• The sensitivity of the film to light.

Film Speed, cont’d

• The higher the ISO number, the more sensitive the film is to light.

ISO 50 ISO 100 ISO 200 ISO 400 ISO 800 ISO 1600

ISO 3200

ISO 6400

Slow Medium Medium Fast Fast Ultrafast Ultrafast Ultrafast

Needs more light

*this is the film speed we use

Needs less light

Film Speed, cont’d

• Film speed also determines grain.

ISO 50 ISO 100 ISO 200 ISO 400 ISO 800 ISO 1600

ISO 3200

ISO 6400

Slow Medium Medium Fast Fast Ultrafast Ultrafast Ultrafast

Fine grain

Fine grain

Fine grain

Medium grain

Medium grain

Coarse grain

Coarse grain

Coarse grain

Film speed, cont’d

Fine grain

Coarse grain

How do you manipulate film speed?