Camera sensor technology has come a long way in recent years but the one thing a camera can't do is to record what the human eye sees. In terms of light's dynamic range, sensors fall short in their ability to record detail in both the whites and blacks of an image at the same time unlike the human eye. Estimates suggest that the human eye can see anywhere between 10-14 f-stops of dynamic range whereas a camera sensor is about 8-11 f-stops. Each yearly improvement in sensor technology brings the camera's dynamic range closer to human sight albeit very slowly.
It's for this reason that in high contrasting landscape shots depending on which exposure mode the camera is set to and where in the image you have the horizon, the result will be either a blown out white sky with no detail and a well exposed foreground or visa versa.
|Exposed for the foreground - blown out sky|
|Exposed for the sky - under exposed foreground|
Always shooting in RAW for the best image quality, once the highlights in a sky have been blown out there's no chance of recovering any detail but there is the possibility of recovering detail from the foreground of an under exposed RAW image to create an acceptable single shot image. The solution that I prefer while the camera is already on a sturdy tripod is to simply take an extra shot and create a three shot HDR (high dynamic range) photograph.
The first two photographs above are unprocessed RAW images out of camera while the finished photograph of Llyn Dinas in Snowdonia (below) is a three shot HDR with the exposure "averaged" out in HDR software. The result is dramatic with detail in both the sky and the shadows. The photograph has punch.
|Three shot HDR of Llyn Dinas in Snowdonia|
The other way of overcoming these restrictions in dynamic range is by using a graduated neutral density filter on a filter holder screwed onto your lens. The "Grad ND" is darker on the top half of the glass filter with the lower half clear and it's designed to balance out the exposure in landscape photography but there is a drawback. They're fine for straight horizons but what about when you're photographing a horizon which are undulating such as mountains, trees or a cityscape full of buildings?
I gave up on "Grad ND" filters many years ago for landscape photography because they're expensive, cumbersome and slow to use and I find the technique of taking multiple exposures and blending them together to be more convenient when shooting and flexible when post processing. If I take five or seven bracketed shots of a scene with the cameras multi metering set to 0 in the viewfinder I can choose in post processing to use a single image to process or any number of them together as a HDR photograph. Shooting a series in burst mode takes a split second and card storage is cheap. Any unwanted shots can be deleted when on the computer.
The biggest drawback to capturing multiple exposures for creating HDR images is movement within the image. Modern HDR software is very adept at correcting "ghosting" in post processing. Often a five shot series of bracketed images in burst mode will be over in a split second and the software can handle minor movement well.
|Pseudo HDR - Below Aber Falls|
Sometimes the movement between shots will be too much for software to handle. In that case a method that I sometimes use to overcome movement is to create a "pseudo" HDR from a single image.
Shooting in RAW, take a shot with a well balanced exposure. You can adjust the exposure slider in your RAW converter to overexpose the shot by 2 stops and save, underexpose by 2 stops and save, then blend the three images together as a pseudo HDR. This technique was used on Below Aber Falls (above) one of my first HDR photos and it's brought out detail in both the moving water and the rocks many of which were in shadow.
The modern technique is tone mapping a single image in HDR software. Tone mapping is a technique used to map one set of colours to another to approximate the appearance of HDR images.
|Three shot HDR - Tower of London|
Creating a HDR image is an ideal way of dealing with difficult lighting in any setting. The photograph of London Tower (above) was taken in a very dark room lit only by the window. It was impossible to capture detail in the shadows of the furniture and the sun filled window in a single shot. This was achieved with a three shot burst bracketed at +-2EV either side of 0EV and processed in Photomatix Pro HDR software. The camera was hand held and braced against a wall for stability.
|Three shot HDR - Dunham Massey|
The same technique and settings were used to capture this photograph of Dunham Massey (above) with light streaming through a window. In fact I've used HDR photography to capture more interior scenes than landscapes due to them only being lit by natural light with a flashgun being barred from use or the building being too vast for flashgun light.
|Three shot HDR - Lady Lever Art Gallery|
|Three shot HDR - Lady Chapel, Anglican Cathedral Liverpool|
|Five shot HDR - One Careful Owner|
The photograph of One Careful Owner (above) taken on the Dee Estuary at Lower Heswall is a five shot HDR bracketed at +-1EV. Is there any more detail compared to a three shot image producing the same dynamic range? It's very hard to tell.
So what software do I use to produce HDR photographs. In my early days I used Photomatix Pro which is available to try and purchase. My software of choice for several years has been Aurora HDR by Luminar. It's very powerful with a huge range of sliders to produce the HDR look that you prefer.
Photographs produced as HDR's have a certain "look" which doesn't appeal to everyone. At worst they can look grungy, but at their best they will have punch and a wow factor but care is needed in toning down a processed image to make it look more natural as the colours can often be overpowering. Every camera has the settings to produce HDR photos. Some even have the ability to do it "in camera" All you need is a tripod or steady hand and the software. Have fun.