HDR Photography

3 May 2013 3:26:16 PM AEST

HDR stands for High Dynamic Range, meaning that there is a high contrast of bright and dark in an image. This is usually achieved by taking the same picture a couple of times (usually three times) with different exposures and combining them into the one final shot. This is not a new technique – the process was pioneered in the 1850s when it was discovered that you can combine different exposed negatives in the darkroom to create an image with more detail and depth. Combining shots meant you could get a photo with detailed highlights and shadows as opposed to a shot with some areas in detail and others over or underexposed, or the happy medium where nothing is quite exposed right and no-one is happy with how it came out.

Zoom forward to present day, and HDR is no longer an effect that can only be achieved by chemically-addled Darkroom Gremlins (I will be the first to confess to spending an unhealthy amount of time in a darkroom developing prints), but also by the digital enthusiast. But how to do it? And more importantly, how to do it well.

Setting up the shot.

Firstly, find your subject. If it is a landscape or portrait shot consider looking at some of our previous blogs with regards to framing and composition of those particular styles. A tripod is highly recommended for HDR work because (and this is important) you need to make sure the camera stays put; otherwise you’ll get a blurry mess. A cable or remote shutter release is also highly recommended to minimise camera shake.

The key to HDR is a process called ‘Bracketing,’ which involves taking a shot with the correct exposure, then taking one a stop overexposed (slightly too dark), and a third shot underexposed (slightly too bright) by the same amount. Yes, there are methods that can combine many photos with a whole range of exposures but let’s keep it simple for now, eh?

Most enthusiast DSLR cameras have an Automatic Exposure Bracketing (AEB or Bkt) function which will do this for you. If you have a more entry level camera you will need to adjust the exposure yourself, either by changing the shutter speed or the exposure compensation. If you have a subject which is moving you will want to use a very fast shutter speed and AWB, use a burst shooting mode if possible.

Combining your Photos.

There are plenty of programs out there which will convert your files into HDR images and, if you are lucky, there are also many cameras which have a HDR shooting mode which does everything within the camera. As with our previous blogs we will go over how to do this in Photoshop, as it seems to be the most common software people are using.

Begin by opening the HDR tool, File>Automate>Merge to HDR. Then select the files you wish to use, from lightest to darkest. Photoshop will then combine the three images (depending on the files and your computers specs this may take some time. Perhaps make yourself a cup of tea or pour a glass of wine?), and show you an approximate result along with a slider and histogram, which adjusts whitepoints. Play with the slider until you get an effect that you like, but remember the purpose of HDR is to provide more detail and contrast in an image. It can be very tempting to go overboard and create images which look like they have been drawn with coloured pencils (very cool if done well, but it’s rare) or have white halos around your subject. Take a browse online and you will see that there is a wide range of HDR imaging styles, but the best tend to be ones that aren’t too obvious and overbearing, but still high in detail (such as the one in the above photo).

It should be noted that this is the very simplified way of creating the high-contrast effect. If you like the results you can save the file and move on. Alternatively, if you want to keep editing simply save to a TIFF or PSD file and keep editing using the normal Photoshop controls.

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