HDR Photography: dealing with a high dynamic range
HDR Photography and Merging Exposures
There are many different types of photography that we can use to create some magnificent compositions. Examples of popular techniques include wide-angle, panorama, fish-eye, black and white, macro and long exposure. One particular technique that can provide some superb results, but is also highly beneficial in certain situations is HDR photography which is a technique of merging different exposures together. This article looks at what HDR photography is, and which types of photograph benefit from this technique.
What are the key components of HDR photography?
As you are well aware, HDR photography is a technique by which you combine several different photo exposures together. The aim of this technique is to provide a balanced photo that shows the detail of both light and dark areas – it provides great flexibility and can create fantastic end-products that balance light and dark areas. The following are the main components of an HDR photo setup:
1. A camera with HDR mode or bracketing mode
First, you must ensure that your camera actually supports this technique as it makes the whole process easier. You can simply alter the exposure manually and take three different shots, but it takes time and whilst you are changing settings, you could disrupt your composition. Using a built-in HDR mode or bracketing mode is a great time-saver and will ensure that you get the best results – most modern DSLR cameras will have such a feature.
2. Two or more exposures of the same photo
This is the crux of an HDR composite and it is impossible to create an HDR photo without at least two different exposures of the same photo. The ideal photo range is 3 shots – one exposed at the normal range, one under-exposed by 1 or 2 stops, and one over-exposed by 1 or 2 stops. The underexposed shot should capture the highlights and lighter detail, whilst the overexposed shot should capture the detail of the darker areas. The normal exposure shot serves as a benchmark and a middle-ground between the two. Two exposures can work, but for the best results, we recommend 3 exposures using the above methodology.
Here is an example of 5 brackets:
3. Post-processing software that can merge exposures using HDR
Finally, you need a piece of post-processing software that can merge the different exposures together. Some cameras actually have a fully-fledged HDR mode that merges the exposures and creates a JPEG composite within the camera. Whilst this is a neat feature, for best results, it is advisable to use post-processing software. You can use either special photo editing software dedicated specifically to working with HDR (like Aurora HDR, HDR Efex Pro, Photomatix) or advanced programs like Adobe Lightroom or Photoshop.
Here is the result after merging all the brackets above (with Aurora HDR):
After merging exposure, you can always edit your photo to fix imperfections, reveal more details and make it more appealing.
Here is the difference between the usual (EV 0.0) photo and the final image:
What types of photo are suited for HDR compositions?
Now that you understand a little more about HDR photos, we can look at the different types of photo that HDR composites are suited for. It is important to remember that not all photos are suited for an HDR exposure merge – if you use HDR on some photos, the final effect can look contrived and fake, and sometimes downright silly. The following are some of the main types of photo that lend themselves to HDR merging:
HDR Portrait by Laura Tillinghast
Portraits in sunlight
Lighting is vital in photography – without lighting, photos can appear bland and two-dimensional. Too much lighting, however, can cause a problem and make objects appear washed out. This is evident in portraits that are taken in sunlight – sometimes the harsh light can create glare and other unfavourable effects. Using an HDR composite in a situation such as this is a great way to reduce those undesirable lighting effects and create a photo that is more refined, but still benefits from the favourable lighting conditions.
Low-light & backlit scenes
Both low-light and backlit scenes usually have a large portion of darker areas that could be under-exposed. For example, if you are taking pictures indoors in a poorly lit area there could be too much shadow. Alternatively, backlit scenes where you have used artificial light to boost the brightness could have areas of contrasting darkness too. An HDR composite that captures the dark areas can greatly help reduce undesirable shadow.
Any shot that has a high degree of contrast, or contrast that exceeds your cameras visual range are suited for HDR compositions. For example, you may have a shot that has washed out areas of sky, together with darker foreground areas that have too much shadow. An HDR composite can reduce these extremes and create a more balanced photo.
Landscape and outdoor photography
Landscape and outdoor photography are also suited to create HDR composites as the sky is often too bright and it can be hard to find a balance between the foreground landscape, and background sky and clouds. If you are taking a photo of a mountain range, for example, the sky and peaks of the mountains may be over-exposed, whilst the base, body and foreground of the mountains could be underexposed. Using an HDR composition could generate a balanced photo that shows all the detail of the mountain and surrounding landscape.
General HDR photography tips
When taking HDR photos, you should never aim to remove shadow and contrast completely – if you do so, the resulting photo will look flat and lifeless – use HDR sparingly and use it to enhance your photos, not to create something completely new. Furthermore, if a photo has a relatively low contrast to start with, there is no point creating an HDR composite as the end-product will literally have no detail or shadow at all.
Regarding editing, your first step should be exporting the photos from your camera to your computer. Next, you should then use your editing software not only to merge the photos together, but also for a final edit and look to improve aspects such as saturation, sharpness, clarity and noise reduction.
We hope you have found this guide useful – you should now have a clear idea of what types of photo are perfect for HDR creations. Why not give this useful technique a try and see how it can enhance your photography.
If you are interested in reading some of Max’s work, you can check him out at PhotoGeeky.com.