|Field Testing the Panoscan
By Liz Hymans
The Panoscan is the first 360 degree digital scanning camera on the market. It was described in the February issue of Panorama, and now we've got the field test report.
Ted Chavalas, a photographer and the Panoscan's inventor, spent a couple half-days training me on the camera, and on a third day he accompanied me up the beautiful and spectacularly located Getty Center in Los Angeles. We had fine clear weather for the morning of "image capture" shown here.
The Macintosh notebook computer used to run the camera sits on its case under the tripod, out of the mud and passers-by kicking range. The opening screen for the Panoscan program has several windows and buttons and is easy to use. What takes time is to understand the functions, capabilities, and interactions between the various manipulations. It's really no worse than understanding the operations of any home entertainment complex or Cirkut camera. And if you get in trouble, you can consult the handy Panoscan Manual (4.5 MB, free download from http://www.panoscan.com). But Ted Chavalas is a patient instructor, and I learned to make the required manipulations out in the field. They consist of adjusting and re-adjusting the settings on the computer (instead of on camera) and running a quick preview scans (similar to making adjustments and taking Polaroid's), and finally running the image capture at the selected resolution.
The first manipulations you'll want to perform on the computer are selecting the ISO, shutter speed, film curve, and shadow detail. With some experience you can guess these settings. A light meter might be useful initially, but is not necessary because you see the results on the preview scan. The basic sensitivity of the CCD scanner is ISO 400. To shoot in bright sunlight you will need to shoot at ISO 100 with the shutter speed at 1/125 and the lens set at F22 (rotate lens on camera, the old-fashioned way). The film curve options are "linear" and "film", which you can set or choose to manipulate on a graph. The shadow detail settings allow more light levels to be assigned to the darker areas of the image where detail is likely to be. "Standard" is useful in studio settings, and "high" or "higher shadow detail" are appropriate for slide reproduction and bright sunlight. The high shadow detail setting has the effect of reducing "noise" (somewhat like film grain) in the dark areas of the picture.
Since many settings interact with one another such as ISO, shutter speed, shadow detail, file size and lens aperture, it is critical that the photographer understand these relationships and how they may effect the final image. This is very similar to understanding film speed, grain, contrast, shutter speed, and aperture on conventional film. The manual has a good section explaining these interrelationships. The "film curve" and "capture conditions" relate to manipulations involving shadow detail and contrast. What you have in front of you is much more capable than any particular film: you can capture detail through a fantastic 11 f-stops of latitude, choose from several levels of resolution (like film grain), and even adjust color balance. It is easy to capture a good image by using the settings recommended in the manual, but it takes time to comprehend and manipulate these elements at the virtuoso level.
Secondly, there are several factors that must be set for individual lenses. These preferences are stored so you only have to adjust them once if you are using only one lens. A chart in the manual recommends settings for different focal length lenses. The settings are for color offset and horizontal scaling, and will indicate corresponding file sizes and the vertical field of view angle. For the field test a Nikon 28mm PC (perspective control) lens was used.
Thirdly, a black calibration scan must be run. You simply put on the lens cap and click the Calibrate button below the camera settings on screen. Whenever you make a change to the ISO, film curve, shadow detail or exposure controls, you will need to run a black calibration. This returns the sensitive receptors to neutral; otherwise the prejudiced receptors can leave streaks on your next scan.
Now you can run a preview scan by clicking on the Preview button on the screen. While the camera rotates, watch the SCSI (pronounced "scuzzy") cable to make sure it moves freely without catching or pulling. The camera will scan 390 degrees and then rotate all the way back to the starting position.
When the preview is done, scroll around the computer screen to view the entire scan and evaluate the image. Make adjustments to the above settings, and use the Color Info area to adjust the gray scale and color balance. This is done by positioning the cursor in a "gray" area of the image and clicking on it (try several, just to see what it does). The entire image is then color adjusted. The fine art of making gray and color adjustments is explained further in the Software Reference Manual, but for beginners, the above procedure works nicely.
When you've made all the adjustments, black calibrated, and are satisfied with the preview scan, it's time to capture the file to disk. To do this, you simply name the file, and click on the "Capture" button. The final 390-degree scan takes from 1 to 15 minutes, depending on the resolution you've selected.
Just as you might think, there are some problems with movement if it's close to the camera. People, cars, waving tree branches or grass blades are subject to either "color tear" (looks like smear), stretch, or partial capture. For instance, a car moving the same direction as the scan will be stretched, and a person walking the opposite direction as the scan might have a squashed head and a footless leg. Waterfalls and waving vegetation will have bits of weird color that can be easily fixed in PhotoShop.
If, during the middle of your scan, a gang of Harley bikers roars through your placid town, a simple click of the mouse will hold the scan until the offending elements pass through your photo, and you can resume scanning. Since you've merely halted the flow of pixels, there's no vertical white stripe - like you'd have with film. This is indeed a handy feature, and we used it several times on the accompanying images.
Now that you have the image filed on your disk, you can export it directly to the client, stitch it at the 360-degree line, perform further manipulations in PhotoShop, imbed "hot spots", burn a CD, or send a thumbnail by e-mail. This is another area where expertise takes time . . . or money. You can learn to perform the manipulations yourself, or hire this out.
This concludes Panoscan 101, and describes the basic elements considered in the steepest part of the learning curve. From here on, it would benefit the user to review the manual several times and just go out and work with the camera. Ted Chavalas says, "You will learn the system best by using it."
In addition to the basics, the image can be rotated on screen, cropped to 360 degrees, or any portion of a full scan. A section in the manual covers trouble shooting and cleaning. The system can also be synchronized with a turntable to record "object movies" - views showing all sides of the object on the turntable.
I was very pleased with the results of the scans: the images are sharp and can be greatly enlarged. One great advantage of printing from digital files is that, once all manipulations are done, the final print is consistent. I can ask my printer to reproduce an accurate copy without sending a reference print or detailed instructions about burning, dodging, and color filtration.
Ted Chavalas was a good instructor. Since he's the inventor, he knows everything you'd want to learn about the camera, and much more. His explanations are clear and he adjusts well to the student's skill level. A good understanding of the relationships between film speed, grain, contrast, shutter speed, and aperture will greatly assist the aspiring Panoscan operator.
Since the camera is expensive (around $27,000 to $33,000), it is recommended that a prospective buyer have a good client base before purchasing the camera. A good alternative is to pay for some lessons and rent the camera until you have enough information to make a purchasing decision. The partners in Panoscan not only designed the camera, but also considered business and development options. It's worthwhile to call them and discuss their ideas. They offer the camera for sale or rent, as well as image capture services. Someone considering purchase might do well to be one of the photographers cooperating with Panoscan to provide that service.
Below are three images Liz captured with the Panoscan.
For more information contact: Panoscan (818) 908-4641 http://www.panoscan.com