High Dynamic Range Magic
NEX-6, 18-55mm E-Mount Lens @ 27mm, Aperture Priority Mode, 1/60 sec, ISO 1000, f/16, Auto Bracket Exposure Mode (13 shots combined using HDR Darkroom Pro)
This weekend’s post is all about High Dynamic Range (HDR) photography, which is the name given to a style of photography that allows you to create an image with perfectly exposed areas across the entire shot – even if this is not possible ‘in-camera’. When the human eye looks at a scene, it is able to distinguish detail in both light and dark areas (unless it is blinded by extreme light of course), but when we take a photograph of the same scene we must tell our camera which area of light we want it to bring out the most detail in. This means that the most shaded areas may come out black and the lightest areas white, whilst the focal point of the shot should be perfectly exposed. It also allows us to under or over-expose large areas of an image for artistic experimentation, such as when you want to capture a silhouette against a bright background.
Even though my focus here is on the foreground, I chose to expose this shot for the sky, to capture the colours of the sunrise in Cromer, Norfolk. This allowed me to turn the foreground into a sharply focused silhouette.
Obviously there are many times when an image is evenly exposed across the range simply because of the way it is lit (naturally or unnaturally), and in such cases HDR photography is not required. Having said that, the effects that can be achieved from using such a technique can often be considered to be interesting, and so it is fairly common for people to use it for more artistic reasons than practical ones. I was visiting St Andrews a couple of weekends ago, which is where I took the featured shot, and I experimented with a few different subjects, to see how the HDR treatment would effect them.
This HDR image of St Salvator’s Chapel is not quite so unrealistic as the featured shot, with areas of shadow still fairly visible.
I think my above shot of St Salvator’s Chapel is probably a respectable reason for using HDR, allowing the subject to still appear fairly natural, and not so obviously manipulated, whilst bringing out detail in all areas of the image. I would say that my featured image lies somewhere between the two extremes of HDR though, as it definitely brings out the detail across most of the image, but it also gives an unnatural feel to the shot – a sort of cartoony look, as though things are made out of plasticine. An averagely exposed image of this scene would look something more like this:
Average exposure of Castle Sands in St Andrews, which allows for some detail in both the bright sky and darker foreground to be captured.
As I was pretty much shooting in to the Sun, I was never going to get an evenly exposed shot of both the sky and the rocks by taking just one image with my camera. I knew that I would have to take a number of shots, with different exposure levels to take account for both the bright sky and dark shadows, and then combine them using HDR computer software when I returned home. The NEX-6 does actually have an HDR setting, whereby the camera will rattle off three shots in quick succession at different exposures, before combining them in a final JPEG image. However, I have started getting used to shooting in the RAW format, and I also wanted to have some control over how the final HDR mix was going to look, so I used the Exposure Bracketing feature of the camera to take 18 photos from -3 to +3 exposure, and various other points in-between. I won’t show you all 18 photos, but here are the two extremes of over-exposed and under-exposed:
Over-exposed shot, at +3 exposure compensation. You can see a good amount of detail in all but the very darkest areas of the foreground.
Under-exposed at -3 exposure compensation. You can see details in the sky, but the foreground is practically in darkness.
When using the bracketing feature of the camera, the NEX-6 allows you to take three continuous shots – one under-exposed, one over-exposed and one at standard exposure, and it also allows you to change how far this exposure range moves, at varying degrees from 0.2 to 3.0. In order to take the 18 shots, I had to use this feature and change the exposure bracketing amount six times, but this also meant that I had 6 photos at the same exposure compensation of 0 – I only needed to use one of these in the final combined image of course. To create the HDR image, you need to combine all of your shots together, and this means that your photos have to line up pretty much perfectly throughout the entire range that you take.
A slightly different view from the same spot – I have added a faux tilt-shift effect, by blurring the image but leaving a diagonal line of focus along the rocks.
I have used pretty cheap HDR software to convert my images, and it does have a feature that will align your photos pretty well. However, if you plan on taking more than a quick hand-held burst of shots, you will need a good, sturdy tripod to hold your camera in one place whilst you change the exposure settings before each shot, or else even the most expensive HDR software isn’t going to be able to line up your images successfully! Whilst on Castle Sands beach, I shot one more subject with the intention of creating an HDR image.
I came across this drift wood lying on the sand, so decided to incorporate it in the composition.
One problem that I have found with trying out various different types of photography in such a relatively short period of time is that I tend to take images for the purpose of trying out a certain technique. This means that I concentrate more on a technique than I do on the composition, focus and camera settings that would create the most pleasing final image. Take the above photo as an example – I was more interested in including the various aspects of foreground rocks, driftwood, shadows etc. so that I could see how the HDR treatment would work on it. This is fine from a learning point of view, and for demonstration purposes on this blog, but it is also really frustrating when I get home and see missed opportunities!
This was taken by the side of the M62 one Winter morning, when I decided to get up to catch the sunrise. I took a few shots to find out how the HDR effect would look in this scene. From what I have seen of other examples, landscapes tend to look better when there are plenty of clouds in the sky.
Once you have combined the images using your chosen HDR software, it is on to choosing the strength of the effect you desire. As I have mentioned already, you can choose a natural look, which is something that an in-camera HDR shooting mode would tend to give you, right the way through to a crazy-looking effect where colours are so vivid and everything looks as though it could be a painting. One of the most dramatic effects can be seen in a cloudy sky, such as in this next image where the clouds look as though they are from a different image altogether.
Another of my off the cuff test shots, where I have not paid enough attention to the scene. This was actually taken on the Sony NEX-5R, when I got to go to London and try out the camera just before its release last year.
HDR photography isn’t just limited to colour photography – in fact, some of the best examples I have seen are in black & white. Again, the effect can be varied, which can depend as much upon your subject and its lighting, as it can on how much you push the sliders to the right in your software package. I took some shots of the ruins of the castle in St Andrews as well, but the light was pretty even throughout the entire image to begin with anyway, which seemed to reduce the possibility of creating a strong HDR effect. I decided to convert the final image to black & white actually, more for my own amusement and education than anything else I suppose.
St Andrews Castle ruins, which sit just above the Castle Sands beach.
I had experimented with black & white HDR photography briefly in January this year, when I had gone on a night photography course with Manchester Photographic Society. I took shots of Manchester Town Hall from a couple of different angles, with this purpose in mind, and due to the contrast in the scene caused by light and shadow on a building at night, the HDR effect is much stronger in these images.
I really like this shot, and was tempted to use it as the featured image, but chose the beach because the colour gives a better understanding of the technique.
The HDR effect is slightly weaker in this shot, but still gives an otherworldly feeling to the Town Hall.
The second image above shows a good example of how different shots are layered together – as the wind was blowing a little, you can see a double exposure of the flag to the top left of the image, as my HDR software could not align the two different positions of the flag.
HDR photography is something that is quite popular at the moment it would seem, and whilst I do really enjoy looking at some of the amazing shots people have taken I think that it can be over-used just for the sake of it. It is something that I am keen to continue exploring of course, and it will no doubt appear at other points during the course of this project. Until then, I’m going to try and concentrate on thinking about my shots as much as the techniques that I am trying to use when taking them.
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