f/stops, apertures, ISOs, & manual

exposures

- introduction to photographing in manual mode with a dSLR -

- introduction to photographing in manual mode with a dSLR -

| basics |

There are 3 settings you need to think about when photographing manually:

❖f/stop (aperture)❖shutter speed❖ISO

- introduction to photographing in manual mode with a dSLR -

| basics |Think of these three settings like an equilateral triangle

ISO

Shutter Speed

f/stop (Aperture)

if you change one of the settings, you will need to change the other two, so they balance.

- introduction to photographing in manual mode with a dSLR -

| basics |❖ f/stop: controls the amount of light coming into

the camera through the lens

❖ shutter speed: controls how long the shutter remains open to allow light to the digital image sensor

❖ ISO: controls how sensitive the digital image sensor is to the light that reaches it

- introduction to photographing in manual mode with a dSLR -

| basics |❖ f/stops, shutter speeds, and ISOs are measured

in ‘stops’

❖ When moving between whole stops, there is a difference of either twice or half the amount of light

‣ f/2.8 to f/4 is a whole stop

‣ 1/125th to 1/250th is a whole stop

‣ ISO 200 to ISO 400 is a whole stop

- introduction to photographing in manual mode with a dSLR -

| f/stops | ❖ f/stops identify the size of the aperture

• remember, it’s adjustable

❖the relationship between the number of the f/stop and the opening is inverse:

❖ the smaller the number of the f/stop, the larger the opening in the lens or

❖ the larger the number of the f/stop, the smaller the opening in the lens

❖common whole f/stops are:

f/2.0 f/2.8 f/4 f/5.6 f/8 f/11 f/16 f/22 f/32

• notice that every other number doubles itself• f/2.0 is a larger opening than f/32 and allows more light

into the camera

- introduction to photographing in manual mode with a dSLR -

| shutter speeds |

❖ Shutter speeds identify the time the shutter is open during an exposure - remember, it’s adjustable and measured in seconds or fractions of seconds

❖ common whole shutter speeds are:

1 sec 1/2 sec 1/4 sec 1/8 sec 1/15th 1/30th 1/60th 1/125th 1/250th 1/500th 1/1000th 1/2000th 1/4000th

Notice that the numerators double each stop, but will be shorter in length moving from 1 second to 1/4000th of a second

When you are outside, you will generally want to use shorter shutter speeds to avoid overexposure

- introduction to photographing in manual mode with a dSLR -

| ISO | ❖ ISO identifies the sensitivity of the digital image sensor to

light - remember, it’s adjustable

❖ the smaller the number of the ISO, the less sensitive the digital image sensor will be to light

❖ common whole ISOs are:

ISO 100 200 400 800 1600 3200 6400

❖notice that every stop doubles itself, and also doubles the sensitivity to light of the digital image sensor

• ISO 100 is much less sensitive to light than ISO 3200

• a lower ISO is better suited to outdoor lighting situations

- introduction to photographing in manual mode with a dSLR -

| BDE |

Basic Daylight Exposure (BDE)

a rule in manual photography that sets a starting point for you to figure out your f/stop, shutter speed, and ISO for normal exposure

BDE is also known as the Sunny 16 Rule

- introduction to photographing in manual mode with a dSLR -

| BDE |

BDE states: Shooting outside, on a sunny day, you will get a normal exposure with ISO 100, f/16 @ 1/125th

If you don’t want to shoot at f/16 or 1/125th or ISO 100, you can choose to change any of those settings and still have a normal exposure, so long as you change the other settings to balance out the change. This is called an equivalent exposure.

For example

• f/16 @ 1/125th ISO 100 = f/8 @ 1/500th ISO 100

• because you changed the f/stop by 2 stops MORE light, your shutter speed needs to be 2 stops LESS light to balance out the equation, and keep the amount of light the same for your normal exposure.