What is exposure bracketing?
As a photographer, exposure bracketing is a way of hedging your bets to ensure you get the correct exposure, which is particularly handy when lighting conditions are difficult to control.
It’s also a lot easier than it sounds. You bracket exposure when you take a series of frames of the same scene at different exposure settings:
- correctly exposed
- and then overexposed
Before digital, and the ability to check the camera’s LCD or histogram for an accurate exposure reading, exposure bracketing was widely used in tricky lighting conditions. Although you can bracket exposures manually, you don’t have to.
Further reading on exposure: The exposure triangle – why is it so important to know?
Exposure bracketing is not the only type of bracketing. To find out about other ways to use bracketing, keep on reading to the end.
Why use automatic exposure bracketing?
Bracketing exposure manually takes time, but if you use automatic exposure bracketing (AEB) it happens instantly with each push of the shutter. So you won’t lose the shot while you’re changing your camera settings.
Bracket exposure for HDR
Some photographers bracket exposure for the express purpose of creating an HDR image.
Exposure bracketing, whether manual or automatic, is ideal for scenes with a higher dynamic range than your camera can handle, but you want to record detail in both the shadows and the highlights.
Here exposure bracketing is used for HDR (high dynamic range) photography and in this instance all three exposures are blended into one image on the computer using Photoshop or similar software.
Further reading: What is dynamic range in photography exposure?
Can you use exposure bracketing in manual mode?
Yes. There are two ways to use exposure bracketing in manual mode:
- You can alter exposure manually by changing any of the three exposure settings, shutter speed, aperture or ISO, in consecutive frames.
- Or you can do it automatically in any shooting mode. In manual mode the shutter speed will automatically change with each frame.
Using automatic exposure bracketing is faster than manually bracketing exposure, but only if it’s already set up. If you have to set it up first, and events are unfolding in front of you, you might miss the shot.
These photos were taken 3 seconds apart. I was shooting in manual mode and simply changed the aperture by 1 stop. I could have changed the shutter speed instead. In the image above the sky is over exposed. In the image below, the sky is correctly exposed, but the foreground and Tower Bridge are under exposed.
Camera settings: Shutter speed 1/250, ISO 200, f11 (above image) and f16 (below image)
How do you use automatic exposure bracketing?
Automatic exposure bracketing (AEB) varies from one camera manufacturer to another and even from one model to another of the same manufacturer. Some camera makes are easier to use than others.
The good news is that automatic exposure bracketing makes the whole process really easy, so it’s well worth finding out how your camera’s system works. For me, the best way to figure something out is just to play with it. If you prefer to follow directions, your camera manual will help you.
How to set automatic exposure bracketing
There are two parts to setting up automatic exposure bracketing. You must decide on the:
- exposure difference of each frame
- number of frames
On my Nikon D810, to set automatic exposure bracketing I:
- push the BKT button,
- then select the number of shots I’d like to take (ie how many photos to bracket it by) by turning the main command dial (the one at the back)
- turn the sub command dial (the one at the front) to select the exposure value difference of each frame (ie to change by a full stop or a third of a stop etc).
I can bracket in differences of 1 stop, 2 stops or 3 stops, and at as little as a third of a stop at a time.
I can also set the number of frames to 3, 5, 7 or 9 frames of bracketing.
So, as an example of automatic exposure bracketing, if I set my camera to:
- a 1 stop difference with each shot and then select 9 frames,
- it will take shots at -4, -3, -2, -1, 0, +1, +2, +3 and +4 stops.
NOTE: if you’re shooting in single servo it’s not just one press of the shutter button. If you select 9 frames of bracketing, you need to press the shutter button 9 times for your camera to cycle through the full range of exposure bracketing you’ve chosen.
Exposure bracketing can also go in just one direction
I can also set my camera to bracket exposure in just one direction – either over or under – rather than one stop of exposure on either side of the “correct” exposure, which is the usual way of exposure bracketing.
So if I set exposure bracketing to -2, it will:
- take a shot at the correct exposure
- then -1 stop
- then -2 stops
If I select +2, the opposite happens.
Not all cameras have a BKT button
My D700 doesn’t have a dedicated BKT button, but I set one of the other buttons to work for exposure bracketing.
Also, it can’t bracket by more than a 1 stop difference at a time, only 0.3, 0.7 or 1 stop. It can, however, bracket up to 9 frames like the D810. The same is true for my old D300.
The basic operation is similar, but as you can see automatic exposure bracketing varies slightly from model to model.
What shooting mode to use for exposure bracketing?
As with all things exposure related, something has to give when you change the exposure. So, once you’ve set your exposure bracketing, you need to decide which shooting mode you want to use.
- manual mode – the shutter speed will change with each frame.
- shutter priority – the aperture will change with each frame and your shutter speed will stay as set.
- aperture priority – the shutter speed will change with each frame and your aperture will change as set.
- program mode – both the aperture and the shutter speed will change with each frame.
How fast do you need the exposure bracketing to happen?
Not every scene is the same. Sometimes you have all the time in the world to get the correct exposure and at other times you have to work really quickly. This will impact on how you use exposure bracketing.
Is it possible that the scene might change?
Set your drive mode to continuous, either high or low, depending on how quickly you need to work through the frames. This way you can press the shutter once and hold it down while the camera clicks through the frames.
Is the scene still?
If you’re photographing something still, such as a bowl of fruit, architecture or a landscape, here’s how to avoid any possibility of camera movement between shots:
- put your camera on a tripod
- set it to self timer
- then set your self timer to a delay of 2 seconds
- and set the number of photos you want it to take (I can do a maximum of 9 on my Nikons).
This way you just push the shutter once and it will cycle through the bracketing according to how you set it up.
Aperture and ISO remained the same throughout.
Recap on how to set up automatic exposure bracketing
- Set the number of frames you want to take.
- Set the exposure difference you want for each frame.
- Decide on which shooting mode to use.
- Decide on how fast or slow you want to cycle through the exposure bracketing and set your drive mode or self timer accordingly.
When is exposure bracketing not helpful?
If there are moving elements in a scene and you’re planning on combining your exposure into one, it will be difficult to blend the images together, as each image will be slightly different from the others
If you’re planning on blending the images, ensure that the aperture stays the same throughout your images so that your depth of field is constant. To do this, shoot in aperture priority or manual mode so that the shutter speed changes instead.
When you’re photographing action your scene will change between each shot, so the chances of the best composition being the best exposure as well is small.
There’s more than one type of bracketing
You’ll have noticed that I didn’t just say bracketing throughout this article, but exposure bracketing. Although exposure bracketing is by far the most common form of bracketing and when photographers refer to bracketing, they usually mean exposure bracketing. However, there’s more than just one type of bracketing. There’s also:
- Flash bracketing
- Focus bracketing
- Depth of field bracketing
- White balance bracketing
Sometimes bracketing is referred to as stacking. Focus bracketing for example, is more often referred to as focus stacking.
Last important note on exposure bracketing…
Remember to switch bracketing off when you’ve finished with it as it doesn’t reset itself back to zero. Been there, done that. Was very confused for a bit.
If you have any questions about exposure bracketing, let us know in the comments.
Also, we love good news, so if our photography tips have helped you to understand how to bracket exposure, share that too.
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