|This sunset panorama of Morro Bay, Calif., has a bright sky and little detail in the foreground. I exposed for the colored sky and opened up the city and bay using tools in Photoshop CS4. Canon EOS-1Ds Mark II, EF 28-135mm lens, eight images, ISO 200.|
Pointers For Panoramas
Q Okay, I admit you have me hooked on composite panoramas, and I’ve been working on perfecting my capture and processing techniques. But two problems keep coming up. First, how do you set your exposure on a panoramic sequence when the light fluctuates from one capture to the next, or when there’s a lot of contrast, such as with a bright sky and dark foreground? Second, I’ve been assembling my panoramas in Photoshop, but I’m getting a result that stretches the outside and compresses the middle. What’s wrong?
A Panorama or not, in any high-contrast situation you must expose for the brighter areas; lost detail in overexposed areas can’t be recovered. Check your histogram to see if the lighter areas are blown out (pixels lined up against the right wall have no detail). Manually set your exposure for the area of the entire scene that contains the brightest area with detail (such as a sunlit grassy area versus a shady area under a tree). Capture every segment of the panorama in RAW format using this same manual exposure. This will underexpose the darker areas, but these can be improved later, using either Adobe Lightroom or Adobe Camera Raw.
If using Lightroom, select all of the images from the panorama sequence, then bring a representative image (in terms of content and exposure variation) into the Develop module to optimize it, using all the tools available to sharpen, open shadows, hold back highlights and improve color, for example. Then Sync the rest of the images in the panorama sequence to the optimized image, so that all improvements are applied equally to each image. Save the images into a folder.
To process the images in Photoshop, first find the files in Adobe Bridge, then open them in the Raw converter. Click on one representative image and it moves to the main window. Then Select All; as you optimize the representative image using the tools in Camera Raw, identical improvements will be made to every image in the sequence. Save the set of images into a folder.
Finally, to composite the panorama, in Adobe Bridge select all of the images in the folder (whether they were optimized in Lightroom or Bridge); select Tools > Photoshop > Photomerge. In the Photomerge dialogue box, choose Reposition (the default Auto skews the assembly with odd compressions and curvatures), then click OK. The program will assemble the panorama, which you can then crop, flatten and finish in Photoshop.
There’s another way to deal with uneven lighting that I’ve been using regularly on panoramas with areas of high contrast. I shoot each image in the composite using HDR (High Dynamic Range) processing of multiple exposures.
The Dark Side Of Wildlife Photography
Q I recently returned from Yellowstone National Park with a set of disappointing pictures of bison and elk. The animals were positioned in sunlight on light-colored ground or vegetation. If the animals were small in the frame, the surroundings were nicely exposed, but the animals were too dark. If the animals filled the frame, they looked good, but the environment was too bright. I used the auto-exposure mode on my DSLR. Do I need to use manual exposure?
A It’s that same old problem of contrast. You have very bright and very dark areas in the same image, and when you choose any of the auto-exposure modes, the metering system on your DSLR will attempt to resolve the problem with a compromise.
Your best solution is to base the exposure on the brightest area of the image (which won’t be the dark animal), either by spot metering it or determining the correct exposure from a similarly lit background and locking it in for your photograph. One more time: Check your histogram to be sure you’re getting the best possible exposure in a difficult situation. If there are pixels piled up on the left side, you have no detail in your dark animals, and if they’re up against the right side, you have burned-out light areas. If your histogram has data against both walls at the same time, chances are that a good representation of the subject isn’t possible with a single capture. (Study up on HDR.) Remember, too, that in any complex exposure situation, you should shoot in RAW format.
If you’ve captured the dark subject and bright background exposed properly for the brightest area, with detail, you’ll be able to work with this image. There are a number of tools that can help you. In Adobe Lightroom, Recovery and Fill Light will restore detail to the bright and dark areas, respectively, if data is there. In Photoshop, you can select the darker subject and lighten it, as well as using Shadows/Highlights for adjustments. In the latest version, CS5, there’s a simple process that will make an HDR from a single image to help control contrast.
If this all sounds way too complicated, remember that in the days of film, we were all stuck with the images you brought home from Yellowstone. If you couldn’t photograph the entire scene with an exposure within a 1⁄2 stop of that required for the subject, you were out of luck. Nothing short of fill-flash on a dark animal would save the day. So don’t despair. Shout “Hooray for digital,” beef up your skills, and get more satisfaction from your photography!
Q I’m making an important presentation of my images on a significant environmental problem using a laptop with PowerPoint and a digital projector. How should I prepare the images for best display?
A The basic thing you need to know about projection display versus how an image looks on your LCD monitor is that the projected image will be less sharp, color gamut will be limited, contrast may be emphasized, and some brightness will be lost.
Process the image so that contrast and color look good on your monitor. Be careful of overly saturated colors because they will be emphasized by the projector and could look blown out, or out of gamut, without detail. Reds and yellows are the most vulnerable. Once the image is as good as you can make it, save it in large format so you can keep it for other uses. Make a new file for insertion in your presentation by resizing.
Most mid-level digital projectors are capable of a resolution of 1024x768, although some new higher-end projectors resolve at 1400x1050 (Canon REALiS SX6 or SX80) to 1920x1200 (full high definition in the Canon REALiS WUX10, about $8,000). Typical LCD laptop computer displays resolve at 1440x900 (MacBook Pro) to 1920x1200 (iMac). Ideally, you’ll size your images to match the projector’s capability, but consider the possibility that you’ll give the program again in the future on a higher-resolution machine.
Because I always want the sharpest image possible for my programs, I size my images at a horizontal width of 2000 dpi, and a vertical image at 1000 dpi wide at a screen resolution of 72 dpi. This exceeds the capability of my current projector (1400x1050), but not the one I hope to be using in the near future!
Outputting the images in JPEG format and compressed to approximately 8 on the Photoshop scale will keep the overall program size small so that the processing power of your laptop isn’t overwhelmed. Even at the projector’s best possible resolution, enlarged images will look softer, so you should sharpen them slightly after they’re sized and just before they’re saved as a JPEG for use in the presentation program.
Q What filters do you deem “must-haves” for digital photography?
Via the Internet
A The most important filter for my own work is the neutral-density filter, which enables a longer exposure in sunlight for rendering milky, flowing water or to lengthen exposure in any light conditions for creative effect. Rather than carry several different filters of different densities, I use the Singh-Ray Vari-ND, which covers a full range, from 3 stops to 8 stops. A gradient ND filter (which darkens only a portion of the frame, such as the sky) is useful in high-contrast situations. While I normally use HDR techniques to control contrast, the gradient filter works better when the subject isn’t stationary, such as when following a herd of animals moving before a bright sky.
Polarizing filters still have a place when the sky needs to be darkened or reflections need to be removed from shiny surfaces. Reflections mask color and detail, and it’s better to accomplish their removal before you get to Photoshop. The blue/gold polarizer is a filter for effect, to cool or warm a scene in a very distinctive manner. It’s not a filter I use often, but it can save the day, and I carry one with me.
Finally, some photographers might use an infrared (IR) filter to achieve the effect of infrared capture without converting their cameras to “pure” infrared. The problem with IR filters is that they lengthen exposures significantly, and they don’t work with every camera due to variations in the effectiveness of the IR “cut-off” filter inside the body. I prefer to work with a DSLR converted to maximize IR capture.
For information about upcoming seminars and digital-imaging workshops, visit www.georgelepp.com. If you have any tips or questions, address them to: OUTDOOR PHOTOGRAPHER, Dept. TT, George Lepp, 12121 Wilshire Blvd., Suite 1200, Los Angeles, CA 90025-1176 or online at www.georgelepp.com.