Photography & Image Rights
03 / Camera & Exposure
Key question
How is a correct exposure achieved?
Whether using a mobile phone or a system camera, every image is created from three values. Aperture, shutter speed, and ISO determine not only the brightness, but also what is in focus and whether motion is frozen or blurred.
Learning objective: You will be able to balance aperture, shutter speed and ISO, set your focus deliberately, and intentionally expose your shots even with a mobile phone.
Three values, one picture.
3.1 / The Exposure Triangle
Aperture, shutter speed, ISO.
Three settings control how much light an image receives. Each has a side effect.
01
Aperture
The aperture in the lens. Wide open (f/2) means lots of light and shallow depth of field; closed down (f/11) means the opposite.
02
Shutter speed
How long light enters. A fast shutter freezes motion, while a slow one blurs it.
03
ISO
The sensitivity. A higher setting makes the image brighter, but also grainier.
Increasing one value by a level offsets decreasing another by a level. This way, you can find the right combination for every situation.
Histogram instead of screen.
3.2 / Check exposure
Histogram instead of screen.
The camera screen can be deceptive, especially outdoors. The histogram shows how brightness is distributed across the image. If it's pushed against the right edge, the highlights are blown out. If it hugs the left, the shadows are clipped.
On a mobile phone, tapping the subject helps set the focus and exposure there. Swiping up or down with your finger adjusts the brightness before you take the shot.
Focus belongs on what matters.
3.3 / Sharpness and Depth of Field
What should be spicy?
Depth of field is the zone that appears sharp. It becomes shallower with a wider aperture, a longer focal length, and a shorter distance to the subject. This is how you make a product stand out against a soft background.
For portraits, the focus is on the eye closest to the camera. For products, it should be on the most important detail, such as the label. A phone's portrait mode simulates background blur using software, which is often noticeable around hair and edges.
Every setting has a side effect.
Exercise
Choose exposure deliberately
Task: Photograph three situations in the Sonnmatt farm shop using deliberate exposure choices.
STEP 1
A jar of honey with a wide aperture against a blurred background.
STEP 2
The farm cat or a person in motion, captured once frozen and once blurred.
STEP 3
The inside of the shop in low light, without flash, with as little noise as possible.
STEP 4
Note down the aperture, shutter speed, and ISO for each image and check the histogram.
Evaluation: Which value made the biggest difference in each case?