Bracketing in Photography: What, Why and How
What is Bracketing in Photography?
Bracketing is a photographic technique to enable you to get better images. That might mean selecting from variations of the same shot or merging images in post processing.
Using this method, photographers capture high contrast scenes that are beyond the technical limits of a camera’s sensor. Also, they acquire sharp focus throughout the frame that would be impossible in a single image. Bracketing also has other less common uses.
A process to ensure optimum image quality, bracketing is most useful for landscape, street, architecture, and macro photography.
Capturing the same image in a series of shots with different camera settings gives a photographer more options to select the best end result. In addition, it opens up possibilities in post processing, such as the high dynamic range image below.
In this post, we’ll take a deep dive into bracketing in photography, mostly exposure bracketing, but touching on other types as well. We’ll also look into the HDR technique, merging bracketed shots for high dynamic range and stacking photos for expanded depth of field.
Why Would You Bracket?
When you’re unsure if the settings you dialed in will deliver proper exposure or the depth of field you envision.
In this case, you can shoot several images of the same scene multiple times with minor tweaks to the settings before each exposure. Then you choose the one that you believe to be the best.
Of the three images in the above screenshot, you might opt for the one in the middle, but it’s not a perfect exposure. However, a bracketed series with incremental exposure settings offers some creative options with editing software.
When we use a post-processing technique to merge photos, we get one image with correct exposure across the frame. That’s closer to the perfect shot.
HDR blending, or merging images in post-processing with a focus stack, allows you to achieve a dynamic range or depth of field that even the best cameras cannot produce. And it expands your creative possibilities.
The Human Eye Vs. Camera Sensors
Modern cameras are technologically advanced devices; however, they’re no match for the human eye. Still, we find some similarities. Both the eye and the camera employ a lens to focus on the subject. And the camera’s aperture and the eye’s pupil allow in adjustable amounts of light.
The technology of image processing is powerful, but the human brain has a far greater ability to sift through information. So the eye can detect a broader range of light and shadows than a single exposure from a state-of-the-art camera.
But digital cameras have the edge when it comes to long exposure photography or image merging. This is especially true on bright sunny days when capturing detail in both shadows and highlights is frustrating.
Types of Bracketing
Here are the principal types of bracketing in photography:
- Exposure bracketing: The most common form of bracketing. Usually, it’s done by varying the shutter speed, although it can be achieved with aperture or ISO as well. A bright sky and dark foreground may force a compromise that leaves one part of the image underexposed or another part overexposed. Exposure bracketing addresses that issue.
- Focus bracketing: Focusing the lens on multiple points in the image, from foreground to background. Then, this series of images captured can be combined into a single photo where everything is in focus, a technique called focus stacking.
- Depth of field bracketing: Capturing several shots of the same scene with different settings to the aperture. Maintain exposure with adjustments in ISO or shutter speed. Choose the image with the preferred depth of field or combine several photos in focus stacking for greater control over the in-focus and soft-focus sections of the finished image.
- Flash bracketing: Use of various flash intensity settings to illuminate different sections of the image. Compare shots and choose the most appealing use of light.
- White balance bracketing: adjust the camera’s white balance to achieve a variety of color tones.
- ISO Bracketing: A series of photos taken at various ISO settings, varying the exposure.
Exposure Bracketing and Camera Settings
Let’s review the exposure triangle of photography: aperture, shutter speed, and ISO. Adjusting any of the three results in a lighter or darker exposure. Aperture impacts the depth of field. Shutter speed may affect image sharpness, especially with subjects in motion, but not so much with stationary subjects. ISO may introduce noise into the image.
Modern cameras offer several types of automatic bracketing. The photo below shows camera settings for automatic exposure bracketing, with a one f-stop increment between each of the three shots.
I recommend using shutter speed for exposure bracketing. With a stationary subject and the camera on a tripod, increasing or decreasing the shutter speed should not cause any problems.
Controlling the camera’s settings is essential to auto exposure bracketing in photography. Operate in Manual mode, in which you dial in the shutter speed, aperture, and ISO. Or you might choose the Aperture priority mode. This gives control of the shutter speed to the camera while you handle the aperture and ISO.
Bracketing could also be achieved with exposure compensation; however, you would take each exposure manually.
For landscape, street, architecture, and real estate photography, exposure bracketing opens up possibilities for technical quality as well as artistic expression.
Set the shutter speed, aperture, and ISO for the series of shots.
Shoot multiple photos at various focal distances throughout the image. Then, stack or merge them to create a single image that is tack sharp front-to-back.
Some of the newer cameras can do this automatically, similar to exposure bracketing. With others, you have to operate with manual focus and make incremental focus changes in each shot. Be careful not to move the camera.
Focus bracketing is essential in macro photography since macro lenses produce very shallow depths of field. It is also useful for landscape photography when you want to capture a depth of field that is impossible with a single shot.
Depth of Field Bracketing
Similar to focus bracketing, but instead of varying the focus for a series of shots, you adjust the aperture to change the depth of field. Maintain consistent exposure with tweaks to shutter speed and ISO.
In post processing, determine exactly what parts of the finished photo you want in focus or blurred. Merge them in focus stacking, giving you greater control over the transition from sharp focus to soft background.
Photographers can take two approaches to flash bracketing.
Take a series of images with varying light intensity from the in-camera or off-camera flash. You can then choose the most appealing.
Another approach is to take a series of shots with different combinations of ambient light and fill flash. Again, choose the most appealing.
Flash bracketing mode is a feature on some cameras and external flashes.
White Balance Bracketing
Of the various methods of bracketing in photography, this is one of the more unusual. Bracketing white balance assigns different color temperatures to a series of images.
This technique is useful for photographers who shoot in jpeg; however, if you shoot in a raw format, the white balance can be adjusted in Lightroom and other photo processing software.
Keeping the aperture and shutter speed constant results in varying amounts of noise and different exposures. This is relevant if noise is part of the aesthetic you seek.
This would also be helpful for shooting high dynamic range photos: if the aperture is fully closed and you don’t want to go to a slower shutter speed, you could bracket the ISO.
How to Bracket Photos for HDR
Before you begin, devise a plan. Have a vision of what you want in the finished product.
Start with setting your camera on a tripod. This avoids small changes in composition that can cause issues with stacking or merging. I take it a step further and add a 5-pound sandbag. It wraps around the legs or hangs from the tripod canopy and adds further stability.
Most cameras have a bracketing mode in the settings. Check the user’s manual for your particular model.
Set the number of brackets, typically three or five. Many cameras go as high as nine. Then dial in the variation in exposure, one or two stops, or possibly a fraction of a stop.
For the optimum number of exposures and bracket settings, check this Adobe chart.
If the camera is set for a delayed shutter, it will take all the exposures automatically. Also, you might use a remote shutter release. This prevents minor camera movement that might result from pressing the shutter release multiple times, leading to problems with stacking or merging the images.
Merging Photos in Lightroom
Now that we’ve covered the types of bracketing and how to do it, let’s load those photos into Lightroom, where the magic happens. The screenshot below shows three bracketed shots in the Lightroom Library, taken with automatic exposure bracketing.
After you load the images into Lightroom, select the ones you want to merge. Under Photo, select Photo Merge, then HDR.
The HDR Merge Preview window appears. Select or deselect Auto Align and Auto Tone as necessary. Auto Tone applies settings for consistent hues across the image. Auto Align will not be needed if the camera remains stable during the shot sequence.
You may see some areas of the image preview that are partially transparent. This is called ghosting. Click the box for Show Deghost Overlay for a display of where this is happening in the photo. Then select None, Low, Medium, or High to remove any ghosting flaws.
The Create Stack selection will group the bracketed images into a stack with the merged image on top. Click Merge.
The merged photo reveals detail in a high-contrast scene that the camera sensor fails to capture in a single image.
Lightroom Alternatives: Photomatix, Luminar Neo, Enfuse
Photomatix allows the photographer to choose a series of bracketed images from its Capture One plugin, merge those images to high dynamic range in Photomatix Pro, adjust the HDR image, then save it to the Capture One catalog. It features a wide variety of HDR tones and styles to create a compelling finished product.
Luminar Neo (Formerly Aurora HDR) features artificial intelligence software with tone mapping technology to expand an image’s dynamic range. You can capture the full range of shadows and highlights by merging together multiple images. Despite being less user-friendly than Lightroom, professional photographers rate it highly. Many praise its robust merge and edit tools.
Enfuse is an open-source Lightroom plugin that can merge multiple exposures to produce realistic images with an expanded dynamic range. It can also merge a series of photos with different focus points to increase the depth of field, a must-have feature for macro photography. In addition, Enfuse can blend multiple shots of night photography in an image stack, rendering an image with a longer exposure than a single shot can achieve.
How to Focus Stack Images in Lightroom and Photoshop
Focus stacking is a photographic technique essential for macro photography. It is highly useful for landscape photography, as well as product, food, interior, and any specialty where sharp focus over the entire image is the goal.
In the screenshot below, an identical composition is captured with six bracketed photos at various focus points.
With a series of images with different focus points, load the files into Lightroom. In the Library module, select the images to stack.
Under Photo, select Edit In, then Open as Layers in Photoshop.
In Photoshop’s Layers panel, select the layers to stack. Under Edit, select Auto-Align Layers. In the window that pops up, choose Auto, then click OK.
Under Edit, click Auto Blend Layers. In the new window, be sure Stack Images is selected and click OK.
The merged image will appear in the main edit window and at the top of the Layers panel.
The result of the six stacked images is shown below, with a sharp focus on the three objects while the background remains out of focus.
Final Thoughts on Bracketing
Bracketing is not a one-size-fits-all solution. And it’s a poor alternative to knowing how to take good pictures. If you shoot sports or wildlife, bracketing is simply the wrong tool.
But for landscape photographers and others in specialties such as macro, product, or real estate, photo bracketing is a problem solver.
Exposure bracketing several shots with different exposures followed by blending these images in post production for HDR photography expands your creative options. Focus bracketing results in tack sharp focus front-to-back, the result of multiple photographs of the same subject stacked in post production. Other forms of bracketing may fit your style.
It’s a technique worth learning. I hope this article gives you the information you need to use bracketing to expand your photography skills.