Photo U – A Journey into Photography Session 2: Understanding Exposure Alex Santiago

Agenda  What is exposure  Elements of Exposure  Exposure Triangle  Depth Of Field (DOF) Explained

What is Exposure?  Exposure is the process of capturing light in a single shutter cycle to produce an image  Exposure that achieves the effect the photographer intended is “correct” exposure

Exposure is Filling a Bucket…  Think of exposure as filling a bucket with water  Things to consider:  Water flow  Time to fill the bucket  Size of hose (wide/thin)  Size of bucket (S/L)

Elements of Exposure  Four Elements of Exposure:  Light  Aperture  Shutter Speed  ISO  Each element is crucial in the process to create a photograph  Each element may be used in creative ways

Elements of Exposure: Light  The most important of the elements  Light creates shadows, highlights, textures, accents, moods, emotions, and other enhancing effects on a scene/photo  Finding good light is a skill that comes with experience and a LOT of trial and error

Elements of Exposure: Aperture  Controls the amount of light allowed into the lens  Adjustable and may be made to be larger or smaller  Controls depth of field (DOF)

Elements of Exposure: Aperture – How it works…

Elements of Exposure: Shutter Speed  The shutter is a curtain inside the camera that opens for a specified duration of time to expose the sensor/film to light  That duration of time is Shutter Speed  Shutter Speed can be used for effects creation in photographs

Elements of Exposure: Shutter Speed  Shutter speed is used for the following reasons:  Determine safe hand hold speed  Stopping action (fast shutter)  Blurring action (slow shutter)

Elements of Exposure: Shutter Speed – How it works…  Safe hand hold shutter speed to prevent blurry images:  Rule of thumb is to always use a shutter speed equal to the focal length  Example: Lens = 50mm SS: 1/50 s Lens: 100mm SS: 1/125mm

Elements of Exposure: Shutter Speed – How it works… Shutter Speed at 2 seconds

Elements of Exposure: Shutter Speed – How it works… Shutter Speed at 1 second

Elements of Exposure: Shutter Speed – How it works…

Elements of Exposure: ISO  ISO is the speed with which your digital camera sensor responds to light  Lower ISO setting will require longer exposure time to create an image  Higher ISO setting will capture the same scene with a shorter exposure time

Elements of Exposure: ISO – How it works…

The Exposure Triangle  The Exposure Triangle is a visual representation of the three ingredients needed for a properly exposed image  The relationship between shutter speed, aperture, and ISO is at the heart of all photography  Understanding the exposure triangle will assist you in creating a properly exposed image

Exposure Triangle: Understanding Stops  Aperture, Shutter Speed, and ISO are adjustable  Shutter speed adjustments are done in seconds or fraction of a second  Aperture adjustments are done in f/stops which translate to the size of the lens divided by the aperture  Lens size/fstop=aperture size smallest Largest Fast Slow Fast Full Stops Chart

Exposure Triangle: Balancing the Elements of Exposure  When we choose an appropriate combination of shutter speed and aperture size that works, it will not be the only combination  There are multiple correct exposure combination for any scene  The best combination is that which provide the effect intended for the image

Exposure Triangle: Balancing the Elements of Exposure  Let’s look at an example:  Aperture: f/11  Shutter Speed: 1/250”  ISO: 100  There are several reasons not to use this settings  Determine the rest of the correct exposure values

Hands on Exercise

Depth Of Field (DOF) Explained – What is DOF?  A camera can only focus its lens at a single point  The area in front and behind the focus point that appears to be sharp is the DOF  DOF has an aesthetic and technical impact on an image  DOF enables you to direct viewers to the focal point of an image

Depth Of Field (DOF) Explained – Shallow DOF  Shallow DOF will help you isolate your subject in an image  The objective is to have the subject in focus while having the foreground/background out of focus

Depth Of Field (DOF) Explained – Ingredients for Shallow DOF  Ingredients for shallow DOF  Large Aperture Size (depending on the lens 3.5, 2.8, etc.)  Long Focal Length ( mm, 300mm, etc.)  Lens closer to your subject

Depth Of Field (DOF) Explained – Deep DOF  Deep DOF brings a majority (if not all) of your photograph into sharp focus  Crucial for beautiful landscape images  Require longer exposure time

Depth Of Field (DOF) Explained – Ingredients for Deep DOF  Ingredients for Deep DOF  Smaller Aperture Size (depending on the lens 8,11, 16, etc.)  Short Focal Length (10- 24mm, 16-24mm, etc.)  Lens further away from your subject

Questions?