Exposure makes the photo — so learn to make the exposure. 

After covering the basics of how cameras work, focal length, and image file types, it's time to look at one of the most fundamental aspects of photography: exposure. 

Since exposure is a big topic, we’ll break it down into manageable parts. We will define exposure, introduce the three settings that control it, and learn how to assess it using the histogram. It won't be long before we go deeper into each setting—shutter speed, aperture, and ISO—so you can understand their individual roles.

What is Exposure?

A photograph is a record of light. Exposure refers to the amount of light that reaches your camera’s sensor and how the sensor processes it to create an image.

You've probably seen photos taken indoors without a flash that look too dark that’s underexposure, meaning not enough light reached the sensor. Conversely, photos that are overwhelmingly bright, with large areas of pure white, are overexposed because too much light was captured.

There’s no single "correct" exposure for a scene. Your creative choices determine how you expose an image. A silhouette against a sunset is intentionally underexposed, while a bright, high-key portrait might be slightly overexposed to create an airy, cheerful effect. Generally, a well-exposed image has a balanced range of tones from dark to light, with details preserved in both shadows and highlights.

Exposure in Numbers

In manual mode, your camera displays three numbers, such as:

f/8 (aperture)

1/50 (shutter speed, measured in fractions of a second)

ISO 400

Changing any of these values affects the exposure. The details of how each setting influences the final image will be covered in later lessons, but for now, it’s important to understand how they interact. 

Introduction to the Histogram

As we’ve discussed, exposure is one of the most important aspects of a photograph. We’ve covered how to adjust exposure, but how do you accurately review it? That’s where the histogram comes in.

One important thing to remember: never trust your LCD screen to judge exposure. The screen is not designed for accuracy—it’s affected by ambient light, screen brightness settings, and the JPEG preview applied to your raw image. You might think your exposure is correct while shooting, only to realize later that your screen misled you.

A histogram, on the other hand, provides a more objective way to evaluate exposure. It looks the same whether you view it on your camera’s LCD or a professionally calibrated monitor. Typically, digital camera includes a histogram display, usually found in an “image details” mode (check your manual). Many mirrorless cameras also offer a live histogram, which allows you to see how your exposure will look before you take the shot—a very useful feature.

What is a Histogram?

A histogram is a graph that shows the distribution of brightness levels in a photo. It represents the range of tones from dark to light:

Shadows appear on the left.

Midtones are in the middle.

Highlights are on the right.

The height of each part of the graph represents how many pixels in your image contain that particular brightness level. A well-balanced histogram indicates a good mix of shadows, midtones, and highlights—helping you assess exposure and make adjustments to avoid losing important details.

Understanding Histogram Adjustments

The histogram makes it easy to see how adjusting your camera settings affects exposure. Increasing exposure shifts the histogram to the right, while decreasing exposure shifts it to the left. However, if the histogram pushes too far and crashes into either edge, shadows or highlights are clipped, meaning detail is permanently lost.

An “ideal” histogram often resembles a bell curve—spread across the entire width of the graph, reaching near (but not beyond) the edges. This is also what your camera’s light meter generally aims for. A well-exposed raw file gives you maximum flexibility in editing, allowing you to fine-tune brightness and contrast to achieve your creative vision.

What About Color?

So far, we’ve discussed brightness, but histograms can also show color information.

• Color data is divided into three channels: Red, Green, and Blue (RGB).

• Some cameras provide individual histograms for each channel, which can be useful when working with strongly saturated colors.

• If a color channel is clipped (pushed too far right), you can lose detail in that specific color, even if the overall brightness looks fine.

Important Notes for RAW Shooters

The histogram displayed on your camera is based on the JPEG preview, not your actual raw data.

This means that even if the histogram suggests some detail is lost, you may still be able to recover it when editing the raw file.

The “Expose to the Right” (ETTR) Technique

Digital cameras capture more detail in highlights than in shadows. Because of this, some photographers use a technique called Expose to the Right (ETTR)—pushing the histogram as far to the right as possible without clipping the highlights. This technique can provide cleaner, more detailed images when processed correctly. Try it out and see if it works for your shooting style.

Aperture refers to the opening in a lens through which light passes to enter the sensor/film. It is typically a circular or hexagonal opening with an adjustable diameter. The size of the aperture is measured in f-stops or f-numbers, a ratio of the width of the aperture divided by the focal length of the lens. 

A smaller f-number (e.g., f/2.8) indicates a larger aperture opening, allowing more light to reach the camera sensor, while a larger f-number (e.g., f/16) represents a smaller aperture, letting in less light. While the numbering system may seem counterintuitive, remind yourself that we’re dealing in fractions. 

The aperture plays a crucial role in controlling the amount of light that enters the camera, affecting the exposure of the image. Additionally, along with subject distance from the background, it influences the depth of field -  the range of distances in the scene that appears in focus in the final photograph. Adjusting the aperture also contributes to creative effects such as background blur (bokeh) or maximizing the sharpness throughout the entire image.

Photographer Slang
When someone says they are stopping down or opening up their lens, they are referring to increasing and decreasing the f-stop value, respectively.

What is Shutter Speed?

In simple terms, it is the amount of time that your camera's shutter stays open when you take a photo. It controls how long light is allowed to reach the camera's sensor. 

Shutter speed is measured in seconds or fractions of a second (e.g., 1/1000 of a second, 1/250 of a second, 1 second). A faster shutter speed (like 1/1000) means the shutter opens and closes quickly. A slower shutter speed (like 1 second) means the shutter is open longer. The longer the shutter is open, the more light that is let in, resulting in brighter images. But, of course it’s not that simple. If the shutter is open, letting in light, it also is continuously recording what’s in front of the lens. 

Shutter Speed Values

Shutter speeds are represented in seconds or fractions of a second. Common values include 1/1000s, 1/500s, 1/250s, 1/125s, 1/60s, 1/30s, and so on - full seconds is also an option. Faster shutter speeds, such as 1/1000s or 1/500s, allow the shutter to open and close very quickly, reducing the time the sensor is exposed to light. This has two main effects: light has less time to hit the sensor/film and there is less time for movement to be recorded. Slower shutter speeds, like 1/30s or 1/15s, result in a longer exposure time, allowing more light to reach the sensor. As you can guess this has the opposite effect of a shorter exposure time - more time for light to hit the sensor/film, and more time for movement to be recorded. 

The real question is how does that function in a practical sense. Controlling the length of time the shutter is open gives the opportunity for both creative decisions and for combatting difficult lighting situations. Longer shutter speeds can introduce motion blur, create smooth-looking water, and opens us up to more advanced techniques like panning. Shorter shutter speeds can freeze action like an athlete jumping, rain drops falling, or cars speeding past. 

Low Light Conditions

In low-light conditions, the available ambient light is often insufficient to achieve a well-exposed photograph using standard exposure settings. To address this challenge, you may opt for a slower shutter speed, allowing the camera's sensor to be exposed to light for a longer duration. 

While this can effectively capture more light and detail in low-light environments, it introduces a potential drawback - the risk of camera shake and resulting blurry images. Slow shutter speeds make the camera more susceptible to the natural movements of the photographer's hand, leading to unintentional blurring in the final image. 

Recognizing this, you can employ various stabilization techniques to mitigate the effects of camera shake. One commonly used method is the use of a tripod, providing a stable platform for the camera during the longer exposure. Additionally, image stabilization features in some camera systems or lenses can help compensate for minor movements. By carefully managing shutter speed and stabilization methods in low-light conditions, photographers can achieve well-exposed, sharp images without compromising on image quality.

Long Exposures

Long exposures involve the deliberate use of very slow shutter speeds, often extending into seconds or even minutes, to create unique and visually interesting effects. Commonly this technique is seen in capturing star trails, light painting, smoothing moving water, and producing ethereal effects in low-light situations. 

When utilizing long exposures to photograph star trails, the prolonged shutter opening allows the camera to record the movement of stars across the night sky, resulting in swirling patterns. In light painting, where additional light sources are introduced during the exposure, extended shutter speeds enable the painter to manipulate and shape the light in the frame. Utilizing a long shutter speed when photographing moving water captures the continuous motion, creating a smooth look. 

In low-light scenarios, employing long exposure techniques can reveal subtle details and textures that might be otherwise imperceptible with shorter exposure times. When photographing a skyline at night, for instance, a longer shutter speed will expose lights from buildings which may not even be noticeable to the photographer. 

Despite its artistic appeal, mastering long exposure photography requires careful consideration of factors such as stability, lighting conditions, and creative intent. The deliberate use of extended shutter speeds offers you a powerful tool to make images that transcend the constraints of conventional exposure settings.

Motion Blur

Motion blur, achieved through intentionally slow shutter speeds (sometimes exceeding seconds), serves as a versatile and creative tool in photography. This technique deliberately extends the duration of the exposure, capturing the movement of subjects within the frame. One common application is in the portrayal of the smooth flow of water, as exemplified in waterfall photography. 

You can leverage this technique to capture light trails produced by moving vehicles during nighttime shots. The elongated streaks of light create a sense of speed and energy, adding a dynamic element to urban scenes. 

Intentional motion blur can be employed to convey a sense of motion in a subject, be it a dancer, athlete, or any moving object. This technique transcends the static nature of traditional photography, offering a visual narrative that encapsulates the essence of movement. Through the deliberate manipulation of shutter speeds, you can create static images which show movement. 

Stopped Motion

There will be instances where you want your subject to be completely frozen in time: sports, birding, and your running kids come to mind. So how do we get our moving subject completely still in an image? This is when you’ll want to use a fast shutter speed. 

The concept of freezing motion through the use of fast shutter speeds is a pivotal aspect of photography. Fast shutter speeds, typically measured in fractions of a second such as 1/1000s or 1/500s, serve the purpose of capturing subjects with precision and clarity, eliminating the risk of motion blur. 

This technique is particularly indispensable in sports photography, where athletes are in constant motion, and the aim is to freeze split-second actions like a sprinter mid-stride or a soccer player striking the ball. Similarly, in wildlife photography, where animals exhibit swift and unpredictable movements, employing fast shutter speeds is essential to preserve the details of the subject without any distortion caused by motion. 

The ability to capture crisp details and freeze action is not limited to these genres alone; it extends to any scenario where the goal is to seize a fleeting moment, whether it be a dancer's leap, a child's spontaneous expression, or any other dynamic element within a scene. In these instances, the use of fast shutter speeds becomes a fundamental tool for photographers to ensure the sharpness and clarity of their images.

The important thing to remember when attempting to freeze motion is that the shutter will close quickly, so less light will have the time to hit the sensor/film. You will need to adjust your aperture and/or ISO accordingly. But, that’s the beauty of automatic modes. Putting your camera into Shutter Priority mode will allow you to set the quick shutter speed you need, and the camera will adjust the aperture and ISO for you - saving you time in adjusting everything manually. 

ISO represents the amount of amplification that occurs to the signal that the sensor receives. A higher ISO represents more amplification, and a lower ISO represents less amplification of this signal, with the greater the amplification resulting in a brighter image of the same scene. Higher ISOs also introduce grain or digital noise to the image - how much depends on individual cameras. 

In film, ISO is a characteristic of the film itself and on digital cameras, you have the ability to adjust the ISO. 

Disclaimer:

This is just a quick overview to set the stage for what we’ll cover in the coming weeks. What’s important to understand now is that these three settings don’t work in isolation, adjusting one affects the others. Controlling exposure is all about balancing them. Think of it as a carefully choreographed dance between aperture, shutter speed, and ISO to capture the perfect shot, and we’re about to learn the steps.

Bokeh Panorama (Brenizer Method)h Shapes

Use a wide aperture to capture a series of images and then stitch them together to create a panoramic photo with a shallow depth of field.

The Brenizer Method, named after photographer Ryan Brenizer who popularized it, is a photographic technique that involves creating images with an exceptionally shallow depth of field and a wide-angle of view, often mimicking the look of medium or large format photography. This method is particularly useful for achieving a unique and dramatic aesthetic, especially in portrait or environmental photography.

Here's how the Brenizer Method works:

Multiple Shots: Take a series of photographs of your subject using a lens with a wide aperture (small f-number) to achieve a shallow depth of field.

Overlap Shots: Overlap each shot by about 30-50% to ensure there is enough information for stitching the images together seamlessly in post-processing.

Stitching: Use image editing software (such as Adobe Photoshop or specialized panorama stitching tools) to combine the individual shots into a single composite image.

Adjustment: After stitching, you may need to make adjustments to ensure a smooth blend between the images. Pay attention to details like alignment, exposure, and color consistency.

The result is a photograph with a wide field of view and a shallow depth of field that might not be achievable with a single shot, even with a very wide-angle lens. This technique allows photographers to create images with a cinematic or panoramic look while maintaining the subject separation and background blur typically associated with wide-aperture settings.

Focus Stacking

Use a small aperture for a deep depth of field, and then take multiple shots focusing at different distances. Combine these shots in post-processing to achieve a sharp image throughout.

Focus stacking is a digital image processing technique used in photography to achieve a greater depth of field than what is possible with a single exposure. This method is particularly useful in macro photography or any situation where capturing a wide depth of field is challenging due to the limitations of the camera's optics.

Here's how focus stacking works:

Capture Multiple Images: Take a series of photographs of the same scene, each with a different focus point. These shots should cover the entire depth of the subject from the nearest to the farthest point.

Software Processing: Use image editing software, such as Adobe Photoshop or specialized focus stacking applications, to align and combine the in-focus portions of each image into a single composite photograph.

Blending and Sharpness: The software analyzes each image and selects the sharpest areas, blending them together to create a final image where the entire subject is in focus

Focus stacking is beneficial in situations where achieving a deep depth of field with a single exposure is challenging due to factors like a close subject distance, the use of a wide aperture, or limitations in the camera's optics. It is commonly employed in macro photography to capture intricate details while maintaining overall sharpness throughout the subject.

This technique allows photographers to overcome the inherent limitations of depth of field in photography and produce images with a level of detail and clarity that might not be achievable in a single shot.

Rear-Curtain Sync

Rear-curtain sync, also known as second-curtain sync, is a flash photography technique that involves firing the flash at the end of the exposure rather than at the beginning. In traditional or front-curtain sync, the flash fires as soon as the shutter opens, freezing the subject at the start of the exposure. 

Rear-curtain sync, on the other hand, synchronizes the flash burst with the closing of the shutter curtain. This technique is particularly effective in situations where there are movement or motion trails, as it allows ambient light to expose the background first, followed by a burst of flash to illuminate and freeze the subject at the end of the exposure. 

To use rear-curtain sync, set your camera to this mode in the flash settings and choose a slow shutter speed. The result is a photograph that captures the flow of motion with the ambient light while concluding with a crisply illuminated subject. To add another layer of creativity to it, you can move your camera as the flash fires, creating light streaks. 

Stroboscopic Flash

Stroboscopic flash is a photographic technique that involves using multiple, rapid flashes of a strobe light during a single long exposure. This technique captures successive phases of motion within a single frame, creating a stroboscopic effect. The repeated bursts of light freeze different moments of movement, producing a sequence of still images in one photograph. 

Stroboscopic flash is commonly employed in situations where continuous motion needs to be represented in a dynamic and visually striking manner. This technique is often seen in dance photography, sports imagery, or any scenario where capturing the fluidity of movement is crucial. 

You can control the frequency and intensity of the flash bursts, adjusting settings to achieve the desired effect. Stroboscopic flash not only freezes fast-paced action but also allows for creative experimentation, enabling you to craft unique and compelling compositions by manipulating the timing and duration of the strobe bursts.

Zoom Burst

Zoom burst is a creative photography technique that involves changing the focal length of the lens during a long exposure. To achieve a zoom burst, use a slow shutter speed and zoom the lens in or out while the shutter is open. This causes the focal length to change continuously, creating a burst or radial streaks emanating from the center of the frame. The effect is particularly effective in emphasizing a central subject or adding a sense of energy and motion to the image. 

You can experiment with different zooming speeds, focal lengths, and exposure times to achieve various outcomes. Zoom burst is often employed in situations where a static composition may benefit from an added element of creativity, such as capturing city lights, fireworks, or even natural scenes, resulting in visually dynamic and/or abstract photographs.

Panning

Panning is a technique in photography where the camera moves horizontally along with a moving subject to capture the subject in motion while maintaining a relatively sharp focus on it, creating a sense of speed and dynamism in the final image.

To execute a successful panning shot, photographers typically set a slower shutter speed to intentionally introduce motion blur into the background, emphasizing the subject's movement. The key is to synchronize the camera's movement with that of the subject, keeping it in the frame and maintaining a consistent speed. To achieve this, photographers often use continuous autofocus and tracking modes to keep the subject in focus while panning smoothly. 

Additionally, it is advisable to stabilize the camera, either by using a tripod or by adopting a stable stance, while following the subject's movement. Panning is frequently employed in sports photography, capturing moving vehicles, or photographing wildlife in motion, allowing photographers to convey a sense of speed and energy in their images through the intentional blurring of the background.