Using a DSLR or mirrorless camera in manual mode can be intimidating for beginner photographers, but it can also be a great way to learn more about photography and have more control over your images, which will give you far more joy than shooting everything in auto. To learn to use your camera in manual mode, you’ll need to grasp how to expose a photograph properly.
In photography, the exposure triangle refers to the three main elements that control the exposure of a photograph: ISO, aperture and shutter speed. These three elements work together to determine how much light is captured by the camera’s image sensor, and therefore how bright or dark the final image will be.
ISO: ISO is a measure of the sensitivity of the camera’s image sensor to light. A lower ISO value (e.g. 100) indicates a lower sensitivity to light, while a higher ISO value (e.g. 800) indicates a higher sensitivity to light. Increasing the ISO allows the camera to capture more light in low-light situations, but it can also introduce noise (graininess) into the image.
Aperture: Aperture is the size of the opening in the lens that allows light to enter the camera. A larger aperture (a smaller f-number) allows more light to enter the camera, while a smaller aperture (a larger f-number) allows less light to enter the camera. Aperture also controls the depth of field in an image, which is the distance between the nearest and farthest objects in the image that appear in focus. A larger aperture (a smaller f-number) creates a shallow depth of field, while a smaller aperture (a larger f-number) creates a deep depth of field.
Shutter Speed: Shutter speed refers to the length of time that the camera’s shutter remains open to allow light to reach the image sensor. A faster shutter speed (a smaller fraction of a second) allows less light to enter the camera, while a slower shutter speed (a larger fraction of a second) allows more light to enter the camera. Shutter speed also affects the way that movement is captured in an image. A faster shutter speed can freeze action, while a slower shutter speed can blur movement. Long exposures can allow the photographer to get very creative, stretching clouds or making waterfalls look beautiful and silky smooth.
By adjusting these three elements of the exposure triangle, photographers can achieve the desired exposure for their photographs. For example, a photographer might use a larger aperture (smaller f-number) and a slower shutter speed to capture a well-exposed image in low light, or they might use a smaller aperture (larger f-number) and a faster shutter speed to freeze action in a well-lit scene.
Here are some steps to follow when using a DSLR or mirrorless camera in manual mode:
- Familiarize yourself with the camera’s controls: Take some time to familiarize yourself with the buttons and dials on your camera. You will be using the shutter speed, aperture, and ISO controls to set the exposure of your images.
- Choose your ISO: A lower ISO will produce less noise (grain) in your images, but will require more light to expose the image properly. A higher ISO will produce more noise but will be able to capture images in lower light conditions. Choose an ISO that is appropriate for the lighting conditions you are shooting in.
- Choose your aperture: A wider aperture (smaller f-number) will allow more light into the camera and create a shallow depth of field (background blur). A narrower aperture (larger f-number) will allow less light in and create a greater depth of field (everything in focus). Choose an aperture that is appropriate for the type of image you are trying to create.
- Choose your shutter speed: A faster shutter speed (1/1000th of a second or faster) will freeze action and is great for capturing fast-moving subjects. A slower shutter speed (1/30th of a second or slower) will create motion blur and is great for creating a sense of movement or for shooting in low light conditions. Choose a shutter speed that is appropriate for the type of image you are trying to create.
- Set the exposure: Once you have chosen your ISO, aperture, and shutter speed, you can set the exposure of your image. Look at the camera’s light meter (usually located in the viewfinder) and adjust the settings until the meter is in the middle of the scale. This will give you a well-exposed image to start with.
- Take the photo: Once you have set the exposure, you are ready to take the photo. Remember to hold the camera steady and press the shutter button gently to avoid camera shake.
- Once you’ve taken your test shot, you may want to adjust the settings, and adjust the exposure compensation dial on your camera to get the exposure right for the scene. Keep a close eye on the highlights and shadow areas to make sure they’re not over or under exposed too much, otherwise it will be hard to edit those areas.
- To understand if you need to make changes to your cameras settings, you’ll need to learn how to read your cameras histogram.
A camera histogram is a graphical representation of the tonal range of an image, showing the distribution of tones from dark (black) to light (white). Reading a histogram can help photographers evaluate the exposure of an image and make any necessary adjustments to ensure that the image is correctly exposed.
Here’s how to read a camera histogram:
- Look at the shape of the histogram: A histogram that is heavily skewed to the left (towards the black end) indicates an image that is underexposed, while a histogram that is heavily skewed to the right (towards the white end) indicates an image that is overexposed. A histogram that is evenly distributed across the tonal range generally indicates a well-exposed image.
- Look at the spikes on the histogram: Spikes on the histogram indicate areas of the image that are heavily concentrated in a particular tone (e.g. shadows, midtones, or highlights). If the spikes are too close to the edges of the histogram, it may indicate that the image is overexposed or underexposed in those areas.
- Look at the overall tonal range: A histogram that is stretched out across the entire tonal range (from black to white) generally indicates an image with a good range of tones. If the histogram is bunched up in the middle, it may indicate a lack of contrast in the image.
Overall, a camera histogram can be a useful tool for evaluating the exposure of an image and making any necessary adjustments. By understanding how to read a histogram, photographers can ensure that their images are correctly exposed and have a good balance of tones.