ISO, Shutter Speed, and Aperture

The exposure triangle is the fundamental concept in photography that determines the exposure, or brightness, of a photograph. It involves three crucial elements: aperture, shutter speed, and ISO, all of which work together to capture a well-exposed image.

1. Aperture: Aperture refers to the size of the opening in the lens through which light passes. It is measured in f-stops (e.g., f/1.8, f/4, f/8). A lower f-stop, like f/1.8, indicates a wider aperture, allowing more light to enter the lens. A higher f-stop, such as f/16, signifies a narrower aperture, restricting the amount of light. The aperture not only controls exposure but also influences the depth of field. A wide aperture (low f-stop) results in a shallow depth of field, ideal for portraits where the subject is sharp, and the background is blurry. Conversely, a narrow aperture (high f-stop) creates a larger depth of field, suitable for landscapes where both foreground and background need to be sharp.

2. Shutter Speed: Shutter speed determines the duration of time the camera's shutter remains open, exposing the sensor to light. It is measured in seconds or fractions of a second (e.g., 1/1000s, 1s). Faster shutter speeds (like 1/1000s) capture fast-moving subjects without motion blur, while slower speeds (such as 1s) are used for long exposures, capturing movement and creating artistic effects like light trails. Shutter speed is crucial for freezing action or capturing motion, depending on the desired effect.

3. ISO: ISO represents the camera sensor's sensitivity to light. A lower ISO (e.g., ISO 100) is ideal in bright conditions, capturing crisp images with minimal noise. In low-light situations, a higher ISO (like ISO 800 or above) boosts the sensor's sensitivity, allowing you to capture well-exposed photos, but it may introduce digital noise, degrading image quality. Modern cameras handle higher ISOs better, but finding the right balance is crucial to achieving a well-exposed and noise-free photograph.

Understanding and manipulating the exposure triangle enables photographers to adapt to various lighting conditions, capture motion or stillness, and achieve the desired artistic effects, making it a cornerstone concept in the world of photography.

This week's assignment was to Take a series of photographs and adjust each image's Aperture, Shutterspeed, and/or ISO. Compare the resulting images. Then write a blog post describing what you learned about the relationship between the aperture, shutter speed, and ISO, and use your images as examples.

I went to the living room and photographed a dead Coral Reef I found when I was Scuba Diving. The Coral has a lot of detail and I really wanted to capture the detail in the reef, grass, and the pavers it sitting on.

Image 1                                   

ISO: 400

Shutter Speed: 1/64

Aperture: F8.4

Image 2                                  

ISO: 400

Shutter Speed: 1/250

Aperture: F7.6

Image 3                                   

ISO: 200

Shutter Speed: 1/250

Aperture: F7.4

Image 4                                                   

ISO: 800

Shutter Speed: 1/320

Aperture: F7.6

Image 5                                                   

ISO: 400

Shutter Speed: 1/600 

Aperture: F6.1

I learned to ensure to record every adjustment to each photo and not get caught in the moment. I after looking through my gallery on my camera I picked number 5. Below is my edited photo using Lightroom.