Exposure is a fundamental concept in photography that determines how much light hits your camera’s sensor when you take a photo. Understanding exposure is essential for capturing well-balanced, visually appealing images. 

We’ll explain what exposure is, how it affects your photos, and how to use exposure adjustments in post-processing to enhance your images.

What is Exposure?

Exposure in photography is like controlling the light entering a room through a window. If you open the blinds fully on a sunny day, the room floods with light, making it bright and possibly blinding. If you close the blinds, the room becomes dark, and you might struggle to see anything clearly. The goal is to find the perfect balance where the light is just right.

The Exposure Triangle

Three main components control exposure: aperture, shutter speed, and ISO. Together, these are known as the "exposure triangle."

1. Aperture

This is the size of the opening in your camera lens that lets light in. It’s like the pupil in your eye, which narrows in bright settings and dilates in darker settings. A larger aperture (a lower f-number like f/2) lets in more light, resulting in a brighter image. A smaller aperture (a higher f-number like f/16) lets in less light, making the image darker. Aperture also affects depth of field, with larger apertures creating a shallow depth of field and smaller apertures creating a deeper depth of field.

2. Shutter Speed

This is how long the camera’s shutter is open to let light hit the sensor. Shutter speeds vary depending on lighting conditions. A faster shutter speed (like 1/1000 of a second) lets in less light and freezes motion, which is great for action shots where you need to catch a split-second moment. A slower shutter speed (like 1/30 of a second) lets in more light, appropriate for low-light conditions, and can create motion blur. 

3. ISO

This is the sensitivity of your camera’s sensor to light. A lower ISO number (like ISO 100) means less sensitivity and less light, resulting in a cleaner image with less noise. A higher ISO number (like ISO 3200) increases sensitivity and allows for more light but can introduce noise into the image.

How Exposure Affects Your Photos

Proper exposure is crucial because it affects how a photo looks. If a photo is underexposed—too dark—details in the shadows are lost. If it's overexposed or too bright, details in the highlights are lost. 

The goal is to achieve a balanced exposure where all parts of the image are clearly visible and detailed.

Using Exposure Adjustments in Post-Processing

Even if you don’t get the exposure perfect when taking the photo, you can still adjust it afterwards using post-processing software like Adobe Lightroom. Here’s how to use exposure adjustments in post-processing to enhance your images.

The Exposure Tool

The exposure tool is one of the few tools that globally changes the entirety of the image. This means it adjusts the overall brightness of your photo. Here’s how to use it effectively:

• Turn on Clipping in the Histogram: The histogram is a graphical representation of the tonal values in your image. Turning on clipping shows where details are lost in the highlights and shadows. By raising the exposure, you can see details lost in the bright spots, and by lowering the exposure, you can see details coming back in those areas.

• Balancing Highlights and Shadows: Using the exposure tool in tandem with other sliders gives you a range of tools to create dynamic depth within your image. Adjusting the highlights and shadows allows you to fine-tune specific areas of your image: lowering the highlights slider can bring back lost details in overexposed areas, and raising the shadows slider can reveal details hidden in underexposed areas.

• Whites and Blacks: These controls allow you to fine-tune the brightest and darkest parts of your image; increasing the whites can make the brightest areas even brighter, adding contrast and pop. Decreasing the blacks can make the darkest areas even darker, enhancing the depth and richness of your image.

• Curves Tool: The curves tool allows for more precise control over the exposure by adjusting the brightness of specific tonal ranges (shadows, midtones, highlights). It’s a powerful tool for fine-tuning the exposure and achieving a balanced look.

5 Practical Tips for Adjusting Exposure

Here are some practical tips for adjusting exposure in post-processing:

1. Use the Histogram. The histogram is your best friend when it comes to adjusting exposure. It helps you see if your photo is exposed correctly, underexposed, or overexposed. Aim for a balanced histogram where the tonal values are evenly distributed.

2. Adjust Gradually. Minor adjustments to exposure and related settings can make a big difference. Avoid making extreme changes unless you want a specific, stylized look.

3. Check for Clipping. Clipping occurs when details are lost in the highlights or shadows. To avoid losing important details, turn on clipping warnings in your editing software.

4. Combine Adjustments. Use a combination of the exposure slider, highlights, shadows, whites, and blacks to achieve a balanced and dynamic image. Each adjustment affects different parts of the image, so combining them can create a more cohesive look.

5. Experiment with Curves. The curves tool offers fine control over the tonal range of your image. Experiment with adjusting the curve to see how it affects the overall exposure and contrast.