Showing posts with label panorama. Show all posts
Showing posts with label panorama. Show all posts

Monday, August 10, 2009

Traveling with a tripod: It's love — Hate

You know, it really is a love — hate relationship between travel photographers and their tripods. Some weigh so much you get tired just looking at them in your room. When traveling with a group, you may get some “evil eyes” staring at you while you take time to set them up and take them down.
Monument Valley, Utah





 Unfortunately, without a tripod, you can’t get really good night photographs, multi-image panoramas, sharp wildlife photos at distance, or sharp macro photographs of beautiful blooms, even with lens vibration reduction or camera image stabilization.

If you don’t have a tripod, or are considering one, but haven’t yet purchased one, it’s time to look at what benefits to travel photography you can derive from taking a tripod with you.
  • Enhance sharpness — The “Photography Hand Holding” rule of thumb, for 35mm camera “equivalent” focal lengths, is the slowest hand-holdable shutter speed is 1 divided by the focal length of the lens. A 200mm lens can be hand held no lower than 1/200 sec. For print sizes of 8x10 inches and larger, even 1/200 is too slow. While some people can hand hold better than others, and lens vibration reduction / camera image stability can help, when you get to it, the rule is accurate. A sturdy, stable, properly sized tripod will get you sharper pictures every time.
  • Create photographic opportunities — There are many photographic opportunities for which a tripod is essential; night photography, time-lapse photography, macro photography, wildlife photography, timed delay exposures, panoramas, etc. You might use a tripod to be creative such as in action photography where you pan with the subject and blur the background to show movement.
  • Use lenses with longer focal lengths — The longer your lens’ focal length, the higher the magnification of your image, the more difficult hand holding the lens will be, and the more likely the image will be blurred by even a minute amount of camera shake. The longer the lens, the more the shake will be amplified. Vibration reduction and image stabilization cannot eliminate camera/lens movement as effectively as a properly sized tripod.
  • Enhance photographic image quality — When you hand hold your camera in low light conditions, you often must either use faster film, or set your sensor ISO setting higher on your digital camera, since there is a lower limit in reducing your f/setting, when you try to keep your shutter speed high enough to hand hold your camera. By placing your camera on a tripod, you can keep your film speed or ISO setting low, improving your photograph’s quality.
  • Enhance depth of field — When you hand hold in low light, you must use a low f/setting, opening up your lens’ aperture to let more light in, and/or a high film speed or ISO setting. Using a low f/setting reduces your photograph’s depth of field. Using a tripod enables you to use higher f/settings, closing the lens’ aperture to create a longer depth of field.
  • Reduce distortion — Some better tripods allow you to get close to the ground for extreme low-angle shooting. This in turn can help you better compose the photograph and minimize keystoning and other types of distortion.
  • Enhance image framing — There’s nothing better than a tripod in assisting a photographer to control the camera/lens position to permit you to perfectly compose your photo by using its panning and tilting movement.
  • Enhance videos — You’ve seen TV cameras at sporting events, news events, and other locations. Many, especially the ones far from the action, are on tripods. There is no doubt that their use for video reduces camera shake and ehances smooth panning to follow movement. With more and more digital still cameras able to take short videos, tripods for those shots are becoming more important daily.
  • Enhance flexibility — You can use a tripod like many photographers to hold more than just a camera. I’ve often used a tripod as a light stand, or to hold a reflector.
  • Enhance photographer’s discipline — In my article, “Get great photos from your camera, instead of whining about needing a new one,” I said, “All too often digital camera ‘users’ just point their camera in the direction of their subject and shoot. No thought goes into photographic composition or exposure.” It takes a bit of time to set up a tripod with a camera and lens. This is a great time to think about your image, set an appropriate exposure, and carefully compose the photograph with thought.”
The Louvre at Night, Paris








 Perhaps you think a tripod is only for expensive SLR or DSL cameras. Think again. If you have a Point and Shoot camera, look on the bottom of the camera. I’ll be you’ll find a threaded hole for attaching a tripod. Tripods work effectively for all kinds of cameras. You just need the right one.

Next week I’ll discuss choosing the right tripod.

Monday, July 27, 2009

Panorama Photography Part II

In Panorama Photography Part I, I discussed what panorama photographs are, and why they’re so appealing.

Now in Part II, I discuss techniques for taking photographs for panoramas created from multiple photographs, and stitched together into a single spectacular image.

There are three major rules of thumb to ensure your images can be successfully mated to make a panorama.
  1. You need exposure consistency in your photographs to ensure colors match from photo to photo which make up your image. One of the most common problems in stitching photographs together is differences in the color of the sky, due to inconsistent exposures photo to photo.
  2. You need to ensure there is enough information in adjacent photographs that they can be successfully “glued” together. This accomplished by photo overlap.
  3. You need to eliminate image parallax so that there are no ghosts in your final image and that lines in the panorama are aligned and look normal.
Galapagos: North Seymour Island

Here are my major guidelines for taking photographs to use in creating multiple photo panoramas:

  • Use a tripod to keep all your photos in the same horizontal plane.
  • If your panorama contains parallel vertical or horizontal lines, such as when the panorama includes a fence or building facade it’s important that your lens’ pivot point, or entrance pupil (the optical center of the lens), not the camera, be located directly over the central axis of rotation of the panorama. It’s relatively easy to locate the entrance pupil of a prime, or zoom lens (each focal point). By rotating your camera/lens over the pivot point, the problem of parallax, where the photographer can’t align vertical and/or horizontal lines in pairs of photographs when stitched together disappears. Really Right Stuff, the manufacturer of my panorama head has an excellent tutorial about locating a lens’ pivot point to eliminate parallax. (Please note, that while Really Right Stuff continues to call the pivot point the “nodal point,” which is an incorrect use of terminology, their method of locating the pivot point is the best way I know of to quickly locate and set the pivot point.)
  • You need to keep your exposure settings uniform throughout your images, so their brightness and color will mesh, photo to photo. You should scan the entire scene making note of the aperture and shutter speeds your camera is suggesting, then pick one pair of settings in the middle, or slightly darker to make sure any sky details are preserved and manually set it, so that the settings will remain the same for each photographic image used in the panorama.
  • Monument Valley, UtahAmply overlap each of the images in your panorama. You wouldn’t have liked my photo of Monument Valley with a white bar in it because I failed to overlap each photo enough. I overlap by 30% each time. Some say 15% works just fine, but I prefer more. Increasing the amount of overlap helps reduce “flaring” that happens when the software is forced to use all of the image frame, including the corners which may show distortion depending on your lens choice.
  • Look for movement in your overall scene. While movement in a scene can make it more interesting at times, too many or large blurry areas in your photos can ruin your final panorama. When overlapping images have items which don’t precisely match, you get a blur, which can ruin the shot. I try to take each of my multiple images quickly to avoid the problem of movement. By the way, I do realize that some movement is unavoidable. You just need to minimize it.
  • Shooting with shorter focal length lenses more often than not introduces problems of lens distortion. When there is lens distortion the stitching between side by side images can be unnatural looking. Many wide angle lenses suffer from barrel distortion to varying degrees. You can avoid this problem merely by shooting with longer focal length lenses.
  • You should also minimize the use of filters, to obtain exposure and white balance consistency between the photos which will make up the complete panorama. Polarizing filters, in particular, often darken the corners of your photographs. Depending on the angle of light to the filter they can create a significant variation in sky color from photo to photo in the panorama, preventing you from creating a combined image which looks as one. I never use polarizing filters when shooting panoramas. For that matter almost any filter can add some vignetting to your images, which interferes with good stitching and the final image, so I normally never use a filter on my lens other than the UV filter which I keep on all lenses to protect them.
  • I normally turn off auto focus and preset my focus manually for the entire group of images which will comprise my final panorama photograph. Image size can change with focus shift. If that happens, it’s likely you’ll never be able to achieve a high quality alignment of your stitched photos which make up the overall panorama image.
  • I manually set my white balance of my DSLR to eliminate color shift from photo to photo so they will seamlessly stitch together. This is especially important for landscapes showing substantial sky.
Good luck. Let me know if these guidelines help you put together your next panorama.

Monday, July 20, 2009

Panorama Photography Part I

When you go to an exhibition of photographs, what type of photo always seems to be one remembered? It’s the sweeping panorama.

Monument Valley, Utah
Panoramas of a scene seem to take the image to new heights. They make landscapes more dramatic and vivid. Mountains become more majestic. Horizons become more exciting. Even a panoramic style view of great architecture becomes more admirable. The above panorama, made from five photographs stitched together, taken in Monument Valley, far better represents the feeling one gets traveling among the Valley’s natural wonders than squarish photographs.

We’re used to seeing photographs in the typical 3:2 aspect ratio of width to height which started with the invention of the 35mm film format, and is carried through on today’s digital cameras, both the DSLR’s and Point & Shoot varieties. The most common print sizes of 5x7, 8x10, and 11x14, generally adhere closely to the squarish 3:2 ratio.

I think that part of the reason panoramas so appeal to the eye is their departure from the 3:2 format, and the easy way they draw your eye across their “canvas.” The appeal of Cinemascope, the first widely accepted “wide” movie format, is much the same. Cinemascope allowed movies to go to a 2.66:1 aspect ratio, twice as wide as the conventional format of 1.33:1. With Cinemascope, the breathtaking beauty of the background of some of the classic movies of the 50’s and 60’s and beyond was greatly enhanced.

Imagine what “Ben Hur” or “Lawrence of Arabia” would look like, reduced to a square screen. Without their wide screen aspect ratio, in my opinion, neither of these films would have won an Oscar for “Best Cinematography.”

The Louvre at Night, ParisYou don’t have to limit your panoramas to landscapes, though they are the most familiar use of the wide aspect ratio photograph. Buildings, city-scapes, groups of people, and parades are all great subjects for panoramas. Isn’t this photograph of the Louvre in Paris at night made more dramatic by its wide aspect ratio?

There are two basic methods for producing a panorama photograph. The easiest way is to take a wide angle view of your subject and crop it to produce an image with a wide aspect ratio. This is how I produced the photograph of the Louvre above.

Some Point and Shoot digital cameras have a “Panorama Mode.” If your camera has one, use it. It will enable you to get some spectacular results with some practice.

The other method for creating a panorama photograph is to take several photos of your subject, moving your camera across the subject, being careful to overlap each shot, then stitch them together with an image editor on your computer. Both Photoshop and Photoshop Elements contain tools to stitch photos together, or you can use specialized software to accomplish this task. I use PanaVue Image Assembler for my multi-image panoramas. It allows me excellent control in creating the combination image.

While you can hand hold your camera to take multiple photographs stitched together into a panorama, I strong suggest you use a tripod. Using a tripod allows you to easily keep each photo in the panorama in the same horizontal plane. I use a special panorama head on my tripod for these shots, which makes leveling the tripod easier, and helps you rotate your camera a specific number of degrees between each photo.

While you’re looking horizontally to produce panoramas, there may be some opportunities for vertical panoramas too. Don’t loose sight of these vertical possibilities.

Hubbard Glacier, AlaskaDon’t forget the “Rule of Thirds” when taking panoramas.

Take my word for it, or try it yourself. Placing the bay’s horizon in the lower third of this photo of the Hubbard Glacier in Alaska, close to the intersection of the lower third with the middle third, made this panorama much more pleasing to the eye, than if I placed the bay’s horizon across the middle of the photograph.

In Panorama Photography Part II, I will discuss techniques for taking your photographs for multiple image stitched panoramas.