Amazing Landscapes Without Using Filters
A technique to balance bright sky exposure without using graduated filters.
- Add a neutral density graduated filter or
- Shoot several frames and merge them using High Dynamic Range (HDR) software.
I had a Lee Filters 0.9 ND grad filter, but the exposure difference between the sky and ground was still far too great, so I either had a perfectly exposed sky and under exposed foreground or a perfectly exposed foreground and over exposed and bleached out sky.
My first thought was to use flash to light the foreground and balance the scene, but even the portable studio flash that I'd taken wasn't powerful enough to illuminate the rocks at the chosen camera settings.
So I had another brain wave - try the magic cloth technique.
With this technique you take two meter readings - one for the darker ground and one for the brighter sky. You mount the camera on a tripod and set the shutter speed and aperture so it exposes correctly for the darker foreground. And then you use a piece of material to mask the sky area so it receives the shorter exposure time that was indicated in your meter reading. I used a ground sheet that I carry around to kneel and sit on when taking low angle shots. You could use your coat sleeve, scarf, hat or even a sheet of dark card. The important thing is that it has a flattish edge that's wider than the lens and is a darker tone to avoid reflections.
Make sure the shutter speed is long enough (several seconds) to allow some level of flexibility and use ND filters if the light is bright. Press the shutter release to begin the exposure and wave the material in front of the lens covering an area approximately the same as the sky. So if the sky takes up around a third of the photo, block around a third of the lens' view. Make sure you wave up and down quite rapidly to avoid a hard line and hold as close to the lens as possible to avoid seeing the material.
This is the scene I was photographing and these two photos show the extremes of the exposure range I was dealing with. Below left was a 15 seconds exposure for the ground and right needed a 1/2sec exposure for the sky.
With this info in mind I set the camera to 15 seconds in manual mode and the material was wafted over for most of the exposure. The good thing about digital is you can experiment with different settings to get the best result.
This was my best attempt, and straight out of camera so I can lighten and darken areas to some degree using a RAW processor. The only downside with this technique is that anything else protruding into the sky area will also be darkened. So the rock on the right is too dark. The same would be true when using a heavy graduated filter though. I did try being clever and made a U shape to avoid blocking the right side but the result looked rubbish.
When there are intruding elements you are better to switch to the HDR method.
Below is the scene at various shutter speeds to record the entire range of tones (the aperture must remain constant). This was then converted in to a HDR image using Photomatix. The technique is explained in more detail here: High Dynamic Range (HDR) explained
And here's the HDR image combined in Photomatix from the sequence above.
The downside to using HDR is when the scene includes moving water, clouds and vegetation which can cause problems. You also have to take several photos and then hope the software blends them well. In this case the result is quite impressive but not always the case. You also have to have more space on your memory card as you end up taking at least three shots of every scene.