Photography - Panoramas
The Panorama is a wider-than-normal picture of a scene, and it is not a new idea. There have been people experimenting with ways to take a panorama since photography became commercially viable in the mid-1900's. One type of professional panorama camera in the early 20th Century, used a long strip of unexposed film laid in a semi-circle at the back of a camera made to hold it that way, while a vertical slit lens on a pivot point was slowly turned by a wind-up mechanism. This would steadily expose only a narrow vertical band of the film to a narrow vertical band of the scene. As the lens rotated, more of the scene was recorded, until the lens reached the end of its travel, and the shutter snapped closed. This was often used to take class pictures in which everyone could get seen better than if they were all clustered into a big group in front of a normal camera. Once in a while, some wise-guy standing at the starting end of the picture would stand still long enough to have his image recorded, then duck down behind his classmates, run to the other end of the crowd, and pop up and pose in time to beat the lens to his new position. This joker would get onto the same class picture twice! It was rare, but it occasionally happened. Ask around at your local Historical Society, perhaps they have one to show you.
Only since the development of Digital Photography has a panoramic image commonly been anything much greater than 180 degrees. The full 360° picture is only a worthwhile prospect if it is being viewed on the computer and interacted with. Ever since I first saw the Star Trek: The Next Generation Technical Manual on CD, I have wanted to create the same effect myself. That CD uses 360° panoramas in various locations on the sets used in the making of the television series to give the viewer the feeling of actually being there. The effect is very convincing and gives one the sense that you are actually roaming about freely on the starship Enterprise, NCC-1701-D, with no Security chapparone telling you not to touch something. Thanks to digital photography and some inexpensive equipment and software, this effect is now possible for the amateur photographer to reproduce.
You don't have to buy a special camera, because this can be achieved with a standard-format camera. In principle, you need to take serveral overlapping pictures of an area while standing in one spot. The pictures you take need to overlap by about 30%-50% and cover the full 360 degree area you are in. Then the pictures need to be run through a program that will seamlessly stitch the pictures together into a very wide single image of the entire scene. The third thing you need to do is to view the finished panorama with a viewer that artifically corrects for distortion due to distance from the camera, and lets you pan around in the image at your leisure.
Step One - Taking the Pictures
To really do this panorama thing correctly, you need the right equipment and software. You will need a tripod to keep the pictures steady and clear. Surprisingly, rotating the camera around the center of the tripod will not yield the best results because of something called Paralax. Paralax is the word used to describe what happens when the close objects and the far away objects seem to move relative to each other when the camera pans past them. This happens when the camera pivots around a point other than a Focal Node. A focal node is like an optical "sweet spot" inside the lens assembly where most of the light coming in from the lens crosses into a pinpoint before hitting the photo-receptor. To correct for this, there is a special kind of mounting bracket called a panorama head, or pan head for short. (No, it has nothing to do with motorcycle engines.) This bracket will let you position your camera so that it is rotating around the focal node of the lens, not your camera's mounting hole. A pan head mounts onto your tripod and lets the camera swivel all the way around while stoping at regular intervals to take a picture. As with the slider bar, you can make one yourself, but investing in buying one is probably the better way to go. They range in price from US$90 to US$800, depending on manufacturer and options. It is worth the price if you plan on taking lots of panoramas.
Actually, there are methods of taking a single picture of the entire 360° area at one time, instead of taking the time to move the camera between every shot. One way is to use an attachment for the lens of the camera that lets the camera look into a parabolic mirror and so see all the way around the camera location. The camera is mounted lying on it's back, pointing straight up into the parabolic mirror. Instead of stitching the panorama together, the preparation process involves stretching the image out so that it lays flat. This also requires special software and hardware (ca-ching!) but can be used to take an instant 3D panorama of a moving scene without telling everybody in the area, "OK, everybody. Hold perfectly still for the next 4 minutes so I can take a picture that you are going to be a very small part of." The lens, mirror and software combination costs between $200 and $400.
You could also mount more than one camera on a mounting bracket, have them all fire in unison, and stitch the images together in the same way you would with a single camera. This was actually done at the Democratic and Republican National Conventions leading up to the 2004 U.S. Presidential Elections. These camera rigs and software were special items invented for the occasions, and carried a price tag of 6 figures each, but it is possible.
Step Two - Stitching the Panorama
But taking the pictures is only the first of three parts. You will also need stitching software. This is a program that warps and blends the separate images you took with your camera so that common points in adjacent images matched up to each other correctly. It then puts them all together to form a single image of the entire scene. There are, of course, several to choose from with varying capabilities. Some are mostly automatic: You feed it a list of the raw pictures (in the correct order), push a button, and presto, a finished panorama! Others allow you to have control over precisely how to attach separate images to each other, what lens you used, where the horizon is in the image, which camera settings were used for each image, and a host of other parameters. This takes some time and patience to accomplish, but the results are often better than the low-end programs. stitching software usually come in two varieties: Those that you buy one time and use as often as you like, and those that will only work if you purchase a stitching license from the manufacturer. (For each panorama you stitch, you use up one license. Licenses can be purchased from the manufacturer at any time, but could cost $10 to $20 apiece.) I prefer the Free variety, myself.
Step Three - Presenting the Panorama
The last step in presenting a panorama is having the ability to view the picture in a website. This is often used to show off the interior of cars, cruise ships, and Real Estate for sale on the web. It also lends itself well to on-line versions of museums. Once again, there are many panorama viewers to choose from with varying abilities and price tags. They will all let the user pan around the image, and some will let you zoom in to get a closer view of the image. Some of the more feature-rich (read: expensive) applications have the ability to include hot-spots. These are areas on the image that you can click on in order for something to happen. It could trigger a sound to play, show a close-up picture of the object the user selected, play a movie showing something happening in the room, or even jump you to another panorama of the next room when you click on the doorway. There are some panorama viewers that are written in Java so that they will work on any browser. Others will require the viewer to download and install a small program in order to view your panorama. Once again, I have opted for the least expensive that is available. (Do you notice a pattern developing here? In my hometown, this would be considered frugal, smart, or prudent behavior. I love my hometown dearly, but I tend to think that everyone there is a bunch of cheap bastards, and I was raised to be one, too.)
It is considered good web ettiqiute to provide a link on your page (if you are distributing your panoramas on the web) to a web site where people can download and install an appropriate browser plug-in. If someone is visiting your web site for the first time and they do not have the necessary plug-in, they will not be able to see your panorama. Installing the viewer is free to both you and your audiance, and is a one-time thing. After the installation of the plug-in, they should be able to see every panorama you have, as well as the panoramas of other websites that use the same technology. (Note: The panorama on this site uses a Java viewing engine. That means that if your browser has Java enabled, you can view the panorama without installing any plug-ins.)
Of course, you could always just view your panorama as a single, wide picture. You might want to print it out on paper and hang it in a frame on the wall. This is often used to display city skylines, like the Las Vegas image at the top of the page. Be warned, though. Due to the proportions of panoramas, you might need access to a printer that can handle longer media than 8 1/2 x 11 inches. If you do not have access to a roll-fed printer at home or work, you can probably find a printing service that can do the job for you. If you can't find one locally, there are a few on the web that will mail you a print of your panorama for a reasonable fee.
I want to point out here that a panorama does not have to be a 360° image. It can be a series of pictures that cover an area larger than you can get with a single shot. As few as two images can be stitched together to create a picture that enhances the subject. Here is another partial panorama that I created last year. Interestingly, even though I have a Panorama Head, I did not use it for either of these pictures. If you are doing a small panorama (2 to 4 pictures), there seems to be more room for fudging in the stitching process. Even so, check out the discontinuity in the windshield strut on the yellow car. Without a Panorama Head, this kind of thing happens often.
PMVR Panorama software by Duckware
August 16, 2005