Olympus DP-10 Digital Camera

In 1998, the Olympus corporation introduced one of the most innovative electronic cameras ever designed for digital photomicrography. The DP-10, illustrated in Figure 1, is designed to fit onto a standard C-mount adapter that is a common accessory for most modern microscopes (Figure 2) equipped with a trinocular head for photomicrography. Controlling the camera is a "hand switch", which is actually an electronic interface to the camera connected through a serial-type computer cable.

Olympus provides serial connectors that allow the DP-10 to be interfaced to both Macintosh and PC computers, and the camera can also be connected directly to an Olympus P-300 digital printer that yields superb photomicrographs in dye-sublimation photorealistic quality.

This remarkable camera has a unique 1.8-inch color liquid crystal (LCD) monitor that displays a real-time preview of the viewfield under consideration with 61,000 display pixels. The LCD monitor allows the microscopist to achieve accurate, sharp focusing as well as perfect framing for every shot. This is a marked deviation from typical digital cameras that require a bulky and space-filling television or digital monitor, which is necessary for the microscopist to view the sample and frame photomicrographs.

A 2/3-inch primary color progressive scan charge-coupled device (CCD) with 1.41 million pixels and on-chip RGB primary color filters provides crystal-clear true 24-bit color reproduction and sharp resolution equivalent to 1280 × 1024-pixel quality in optical photomicrography. The chip camera system features a Through-The-Lens (TTL) central measuring/spot measuring metering mode that allows exposure control through a programmable auto exposure setting with a white balance control. Exposure times can range from a quarter second to 1/10,000 second with the sensitivity of an ISO 200 film equivalent. Digital images are recorded and compressed using JPEG (Joint Photographic Experts Group) format at a resolution of 72 or 144 dpi.

Digital images can also be recorded directly onto the hard drive of a PC or Macintosh computer connected to the DP-10 through a RS-232 serial port. Any TWAIN-compliant imaging program is capable of controlling the DP-10 using proprietary Direct PC connection-TWAIN software that resides on a CD-ROM disk accompanying the digital camera.

The following procedures outline use of the Olympus DP-10 with an optical microscope.

Images recorded on a SmartMedia card can be reviewed by placing the card into the DP-10 and depressing the REC/Play button until the Play indictor LED is activated. At this point, the last image recorded on the card will be displayed on the LCD monitor. Use the +/- buttons to toggle the screen display to other images stored on the card. Individual images can also be erased using this display mode. To erase an image, first use the +/- buttons to find and display that image. Next, depress the Erase button and two options are displayed on the screen: Go will erase the image when the SET/OK button is depressed, and Cancel will cancel erasure when (oddly enough) the Erase button is depressed. If the SET/OK button is depressed, the term "Erasing" appears on the screen, the image is erased, and the previous image is displayed on the screen. It is important not to open the card cover during erasure. Doing so may destroy data stored on the card.

In the Play mode, up to nine images can be displayed simultaneously on the LCD monitor. This is accomplished by depressing the Index button while the camera is in Play mode. When displaying indexed images, the currently selected image is assigned to position number five (5), or the center image if there are less than nine stored images, and is displayed with a small numeral indicating the position in the lower right-hand portion of the image. Other images stored on the card are also displayed in a similar manner. The four preceding images are displayed and numbered 1-4 in the corner and the subsequent four images are also displayed and numbered 6-9 (provided there are nine images stored on the card). The currently selected image has a red image number and the others are displayed with black numbers. Use the +/- buttons to toggle between images and select an image for display on the LCD monitor. Once the chosen image has been selected (has a red image number), depress the Index button to display the image full-size on the LCD monitor. Pressing the Print or Erase button in the Index mode allows printing or erasure of the selected image.

When the optional Olympus P-300 printer is connected directly to the camera box, the hand switch can be used to direct images to the printer. Under these circumstances, all printing operations are controlled from the camera box, and the buttons, print count setting dial and other controls on the printer are defeated completely. If the printer is connected to a computer, the print operation must be controlled by that host computer.

If printing errors occur, they are displayed on the camera LCD monitor. The Printer Offline error message is displayed in red characters when no printer is connected and the print button is depressed, or when the printer's main power switch is turned off. A Printer Error (also in red characters) is displayed when the printer paper jams or the transfer roll is exhausted. When an error occurs during a print cycle, printing stops immediately. After the error has been corrected, depress the SET/OK button to resume printing. Depressing the Print button on the hand switch evokes a print menu with the following selections:

An optional Flash Path floppy disk adapter (Figure 6) is available for transfer of data from the SmartMedia card into a computer. The adapter contains a slot into which the card is inserted to allow file transfer through the floppy disk drive present on almost all personal computers. A CD-ROM disk containing driver software for the Flash Path adapter accompanies the DP-10 digital camera hardware. When loaded and running properly, double-clicking on the floppy drive icon opens a directory containing a single subdirectory named Imolym, which contains the stored images in JPEG format. These images can be copied to the host computer's hard drive and viewed in any image editor or a Web browser.

Connection cables are also included with the DP-10 camera system to interface the camera to an IBM-compatible or Macintosh computer. After loading the accompanying software, images can be recorded directly onto the host computer or another computer residing on the local area network. For more information, consult the instruction manual for the DP-10 microscope digital camera system.

The area of the microscope viewfield that is imaged by the DP-10 LCD monitor and captured by the camera is dependent upon the C-mount adapter and projection lens configuration. If a TV-relay (1x) projection lens is used with the digital camera, a good portion of the viewfield available to the eyepieces will be imaged with the camera. Other adapters, depending upon their relative postion with respect to projection lenses and the type of lens used, will capture varying percentages of the viewfield.

Digital images produced by this camera are on display at various locations on the Olympus Microscopy Resource Center Website. All of the images utilized in our virtual microscopes and the Silicon Zoo were captured using the Olympus DP-10 digital camera.

Contributing Authors

Mortimer Abramowitz - Olympus America, Inc., Two Corporate Center Drive., Melville, New York, 11747.

Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.