Why Bracketing Exposures Could Be The Answer You're Looking For

By Caroline Schmidt. Posted

High-Dynamic Range photography, otherwise known as HDR, is a phrase that is often enough to make many a seasoned photographer shudder. Personally, it brings back vivid memories of an ugly trend that swept through digital photography in the early years of HDR, when snappers realised they could capture multiple images of a scene at different exposure levels and mash the frames together to reveal every single detail in the brightest highlights to the darkest shadows.

Just because we could, did anyone really ask if we should? Certainly my early HDR efforts were largely gaudy, retina-straining creations that looked very unnatural and jarring. Along with tastes maturing (I’d like to think), software has also improved over the years, and HDR merging has gone from quite a specialist affair that requires standalone suites to something that’s supported in almost every editing product you can imagine – and it’s handled much better now than it once was too.

Here though, let’s focus on learning how to successfully capture a bracketed HDR sequence in-camera. One of the most important factors to remember is that HDR is best suited to scenes that are not only otherwise difficult or impossible to balance with filters, but that contain little or no moving elements. Parts of a composition that move substantially between your bracketed exposures will create ‘ghosting’ in your final image. Some of this ghosting can be fixed by clever automated software tricks, but only up to a point – where possible to avoid ghosting you should stay away from scenes with moving elements. That includes the camera too: it needs to be locked on a sturdy tripod to capture good HDR images, and you’ll probably see the benefits of using a remote release – wired or wireless – to prevent the camera from moving between exposures. All set? Let’s get into it…

1. Set-up

For this scene, as the light is blocked from the lake and foreground by the terrain, exposing for the land would blow out the sky and water, wilst exposing for the highlights would render the foreground rocks and land too dark – an ND grad could be used to hold back the exposure on the sky, but this would then leave the reflection in the lake too bright in relation to the sky. In order to capture the full dynamic range, we’ll need to bracket several exposures.

BTS DSLRP HDR

2. How to bracket exposures

Set up your composition, focus and dial in the settings as you would for any landscape exposure. Then, turn on bracketing – this is usually done by holding down a BKT button and dialling in the number of shots you want to take, but varies from camera to camera. You'll also need to set the exposure difference between each shot, in stops of light.

bracketed exposure

3. Take your shots

Here five exposures were taken, each set at one-stop apart. The dashes on the top plate exposure dial indicate this. Before you start shooting, and as a precaution, set your lens to manual focus to stop it from changing focus between frames. Then, using a remote release, trigger the shutter five times (or however many you set) to capture the full bracketed sequence –
in aperture-priority mode, the camera will change the exposure between each frame.

4. Assess and reshoot

Assess the results and the histogram for the darkest and brightest exposures – the darkest exposure should have no highlight clipping, and the brightest should have detail in the shadows. You might find that the ‘middle’ exposure in your sequence hasn’t been metered for correctly in some scenarios. You can adjust this using the exposure compensation feature to set the middle exposure correctly, and then capture your bracketed frames again.

All done!

Now all you need to do is blend the shots together either manually or using an automated action. For a step-by-step on how to blend your HDR images, check back in on this blog Monday to see how the below image was made using the five exposures shown above.

FINAL DSLRP HDR

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