The most common problems encountered with the Nikon DXM 1200 Digital Eclipse camera system are reviewed in this section. Suggestions for solutions are also included, but many imaging problems may arise in the microscope itself. Be sure to check both the camera system (including the computer) and the microscope when difficulties occur.

Problem: The computer cannot capture an image.

Solution: - The most probable cause is that the camera and supporting computer are not properly connected to each other. Shut down the computer and examine the interface board to ensure it is firmly seated in the PCI expansion slot. Remember to disconnect the power cable from the computer's power supply before opening the case. In many cases, it is a good idea to remove the expansion card and re-seat it. If the computer is being used for multiple operations, all system resources may be dedicated to other tasks. Check the task manager to ensure other applications are not consuming too many resources. In the event of an error, follow the on-screen instructions.

Problem: The image is excessively bright or too dark.

Solution: - This error often occurs when the exposure time is set too high or too low, or the camera gain (sensitivity) is not correctly adjusted. Check the microscope illumination to ensure the viewfield is bright and the proper amount of light is entering the camera tube. Check the image RGB levels in the ACT-1 software (the color level monitor) and make sure that none of the signal levels is saturated.

Problem: Images display poor color balance.

Solution: - The most common cause of this error is due to the color temperature of the microscope illumination system. To remedy the situation, insert a color conversion filter to bring tungsten-halide illumination to daylight color temperature levels (5500 K), and set the illumination voltage at the predetermined optimal level for the microscope during photomicrography. Another cause might be an improperly specified white balance with either the camera hardware or the ACT-1 software. Use the White Balance menu in the Live settings panel to adjust white balance. If these solutions do not solve the problem, check the computer monitor to determine if the color adjustment is improperly set or adjust the color at the computer video card level if the driver software will allow this operation.

Problem: Images have low contrast.

Solution: - This is a common problem in optical microscopy, regardless of whether digital imaging or photomicrography on traditional film is being conducted. The cause is often an excessively large setting for the field or aperture diaphragms. Adjust the microscope for proper Köhler illumination and examine the field diaphragm to determine that it circumscribes the field of view. Remove the eyepiece (or insert a Bertrand lens) and examine the rear focal plane of the objective to observe the size of the substage condenser iris aperture diaphragm. Adjust this diaphragm so that it is approximately 70 to 80 percent of the objective numerical aperture or exit pupil.

The utilization of improperly configured optical systems can limit contrast, especially when conducting image-enhancement techniques such as phase contrast, differential interference contrast, or Hoffman modulation contrast. Carefully check the microscope and examine the specimen through the eyepieces to determine if these techniques are providing adequate contrast. In general, to improve the contrast of a monochrome image, insert a green interference filter into the lightpath at some location below the substage condenser.

Other causes of poor contrast are intruding ambient light and low inherent specimen contrast. Turn off the room lights to see if the situation improves, and place a high-contrast specimen on the microscope stage to test for contrast improvement in the ACT-1 software.

Problem: Images are not sharp.

Solution: - Check the microscope focus to obtain a clear, crisp image on both the computer monitor and through the eyepieces. Focus problems often occur when the camera system is not properly mounted on the microscope trinocular observation port. Check that the camera is properly inserted into the microscope's vertical tube, and that the camera has been properly secured with the clamping screws provided on the vertical tube. To avoid excessive vibration, which can lead to severe focusing problems, mount the microscope on a sturdy bench or table that is placed on a flat, level, and solid floor. It is often wise to utilize vibration-isolation equipment in environments that are prone to building, ventilation, or traffic vibrations. In rare instances, poor focus can be due to an excessively small substage condenser aperture opening size. Check the size by examining the objective rear focal plane using a phase telescope or Bertrand lens. If the image has been enlarged too many times by the microscope optics, empty magnification can occur that leads to "soft" images. Always restrict the magnification factor to a value between 500 and 1000 times the numerical aperture of the objective.

Problem: A noise grid or streaks occur in the digital image.

Solution: - This error can occur for several reasons, but the most common is an improperly set white balance or digital enhancements having the sharpening factor set too high. On rare occasion, the inter-pixel stepping device can cause a basket-weave effect in the background that affects the image. If this happens, try recapturing the image under a slightly different set of software conditions.

Problem: The computer will not allow installation of the ACT-1 software.

Solution: - There may be insufficient available memory (RAM) or the computer's hard drive may be too full. If the operating system is not compatible with the software, an error message will inform the user that the software cannot be installed. Do not attempt to install the ACT-1 software on a Macintosh or Windows 95 (or earlier) computer. If the hard drive is full, delete unnecessary application programs and be sure to close all applications prior to installing the camera support software. Computers having too little memory (RAM) will require a hardware upgrade.

Problem: The ACT-1 software will not launch.

Solution: - Either the camera is not connected to the microscope or the PCI interface board is not properly connected to the computer motherboard. Reseat the board and check the camera connection. Close any other application programs that may be running and check to ensure the computer has sufficient memory to start the software.

Problem: A sudden halt occurs with the ACT-1 software or it runs improperly or very slowly.

Solution: - This problem is most likely caused by interference by another application program running simultaneously that is consuming too many resources. Shut all other applications down or reboot the computer for a fresh start.

Problem: No live image is presented in the display window.

Solution: - Check to make certain the exposure range is properly defined within the ACT-1 software, and examine the microscope adjustment. The optical path should be aligned with the camera and the illumination and focus position should be correct. If the microscope appears to be functioning properly, check all parameters in the ACT-1 software, such as camera gain (sensitivity) and exposure time.

Problem: The software will not save image files.

Solution: - The problem is insufficient hard drive space. Clear unnecessary files, or install an additional hard drive. In some situations, the image resolution, and corresponding file size, may be reduced.

Problem: The software will not print images.

Solution: - Either the printer is not properly configured in the computer software, or it is not connected to the computer. In many cases, especially if the printer has been functioning properly, it may be out of paper or ink (toner).

Problem: Images from the printer have too low of a quality.

Solution: - This is usually caused by the printer being set to a low resolution, or not being able to reproduce images at high resolution. Check the printer instruction manual to see if there is a remedy.

If you encounter problems that are not addressed here, please send us an email so that we can analyze the problem and possibly offer a solution.