Landscape photographers have been challenged by the range of tones in real life compared to what they can capture with the camera. This was true when Ansel Adams was shooting black-and-white large-format images 60 years ago, and it’s true today for digital photographers. Sunlight and shade can be too much for even the best of sensors.
High Dynamic Range photography (or HDR for short) changes all of this. This technology allows you to take a series of exposures of a single scene and merge the range of tonalities that you get from those exposures into one image. This means that you aren’t as limited by technology, but actually can capture something closer to what you really see in the real world. It works especially well with landscapes because you usually don’t have moving objects within them. Movement can be a problem across multiple exposures.
|Auto-bracketing is a key part of HDR photography. Experiment with setting up your camera for a series of auto-exposures at one- or two-stop differences.|
In many ways, this is similar to how Ansel Adams used to photograph and process his film. He’d meter the range of tonalities within a scene and set his camera to record specific brightness levels based on those tonalities. Then he’d go into the darkroom and process the film according to the range of the tonalities. Adams would vary his exposure and processing depending on the differences in tonalities for a specific scene. HDR also allows us to change the way we photograph to best capture the / tonalities within a scene.
This is exciting to me—I’ve started to take photographs of scenes that I never would have attempted before because the light just wasn’t right. I’ve also been able to take photographs of scenes that were literally impossible with traditional means. HDR also allows photographers to take pictures of scenes during times of day that never really worked with color photography before.
The latest version of Photoshop can process an HDR image, but few photographers I know use Photoshop for HDR. I don’t care for it either. Most photographers today use a program called Photomatix from HDR Soft (www.hdrsoft.com). At $99, this is an inexpensive program in today’s world of photo software, and it’s easy to use.
Shooting For HDR
To create an HDR image, you need a series of photographs taken of the same scene at different exposures. While some people believe you should shoot RAW for this, I don’t think that’s necessary. You can shoot RAW, but you’ll have increased processing times and not that much extra in the final image. Because you’re combining tonalities from multiple exposures, even JPEG files give you sufficient tonalities with which to work.
Here are the shooting steps for HDR:
1 Set your camera on a tripod. You need to be able to get all of these exposures lined up identically on the scene. Using a tripod is the easiest way to do that.
2 Set up your camera for an optimum midrange exposure for the scene. Because you’ll probably be shooting a scene with a wide range of tonalities, this means that highlights are usually too bright and shadows are too dark. That’s okay because this isn’t your only exposure. I’ll often take a picture and check my histogram to be sure I have a midrange exposure. Look to see that your histogram is more or less centered in its range.
3 Take a series of exposures that are at least a full stop apart. An easy way to do this is to set up your camera for auto-exposure and auto-bracketing, then set your shooting speed to continuous. On my Olympus E-3, I can set up auto-bracketing for three or five exposures at one-stop differences. Other cameras can be set up similarly to do auto-bracketing in one- or two-stop differences. This is something with which to experiment a little to get it right for your own gear.
4 Auto-bracketing enables you to shoot without a tripod if you stabilize the camera. In the photographs you see here from Montaña de Oro State Park near Los Osos, Calif., there was no way to use a tripod. I used a beanbag on the rocks to steady the E-3 (the E-3’s tilting LCD allowed me to see what the camera was seeing). Then, by combining auto-bracketing with continuous shooting, I just held the shutter down for the five exposures that gave me my sequence, with each photo one ƒ-stop apart in exposure.
Combining The Photos
Once you’ve downloaded your pictures onto your hard drive, you can combine them into an HDR image.
Here are the Photomatix steps:
1 In Photomatix, go to the menu labeled HDR and select Generate. Photomatix has a lot of menus, but you don’t have to use anything other than HDR.
2 Using the dialog box that opens, load differently exposed images onto Photomatix. Click on Browse to find specific images to import from your computer’s files. This is sometimes challenging with the small thumbnails that display in your operating system’s file-opening boxes. I typically use Adobe Bridge or Lightroom to help me find the photos that have a range of exposures.
3 Click OK, and Photomatix will show an Options dialog box. Usually, you’ll just go with the default as shown here. If there was movement in your photograph, check “Attempt to reduce ghosting artifacts,” which sometimes helps.
4 Click OK, and let Photomatix go to work. This can take some time, depending on the speed and power of your computer.
5 An unattractive image will appear. This is the HDR image with all the information you need, though it’s not displayed in a way we’re used to seeing.
6 Click on HDR > Tone Mapping. This is where the real magic occurs in Photomatix and for your HDR image.
7 You’ll find a dialog box with a lot of controls that allow you to further adjust your image, though your picture may look great right from the start.
There are a number of other controls in the dialog box:
• Nature photographers usually find that the Light Smoothing control looks best at the Very High setting to the right.
• You can try changing the Strength of the HDR Tone Mapping and the Color Saturation. Photomatix sometimes makes the colors a little too saturated.
• Luminosity affects the brightness of the image.
• The next section includes White Point, Black Point and Gamma. White Point affects highlights—use caution with it. Black Point adjusts the blacks in the photo—be sure they’re strong enough. Gamma affects the midtone brightness and contrast of the image.
• At the bottom of the box, you’ll see a series of numbers: 512, 768 and 1064. These are sizes of the preview image in this dialog box.
• You can leave the rest of the settings as they are if you like the photograph. Frankly, I don’t find the need to change much else for most images. The Color tab gives additional control over the color of the image, including its warmth and saturation of highlights and shadows. Micro offers subtle changes in detailing, and S/H affects shadow and highlight smoothing, but usually the overall Light Smoothing at Very High is fine.
• The image now can be processed based on these settings by clicking Apply. You can choose output of either 8-bit or 16-bit. If you think your photograph is ready to go, 8-bit is fine. If you think it needs a lot more processing in Photoshop, then choose 16-bit.
8 Finally, save your processed image as a TIFF file that can be used as is or go into Photoshop. Generally, I open the photograph in Photoshop because I may find small adjustments that need to be made here and there in the photograph.
That’s all there is to it, except for you to go out and start taking pictures! If you want to explore new ways of seeing the natural world, and ways that are truly closer to what we can see with our eyes, give HDR a try.
Editor-At-Large Rob Sheppard’s new photo blog is located at www.photodigitary.com, and his latest book is the totally revised New Epson Guide to Digital Printing.