New Developments in Microscopy Documentation
Anthony Borrelli and Marc Neiss
Reprinted from American Laboratory October 1999
Many researchers can recall their first experience visualizing the unseen micro-world through the eyepiece of a microscope. Although this experience was captivating, it was not always easy to capture and share one's observations. Researchers today can capture images using 35-mm, instant film, video cameras, digital cameras, and now digital video cameras.
When looking to purchase an image capture system, it is important to understand each technology's strengths and weaknesses, along with individual imaging needs including cost, work flow, image quality, and how the viewer intends to use the images, to choose the best system for the laboratory.
Although silver halide (film) technology still remains the most established technique for documenting images through the microscope, video and digital imaging solutions that offer a real-time preview are commonly being used. Video cameras have been around for several years and provide one option for photomicrography documentation. Digital cameras and now digital video cameras designed for microscopy offer scientists spatial resolution comparable to film and the ability to enhance images in real time. Until recently, using digital technology for research has traditionally been an expensive proposition.
Film-based systems typically offer the highest resolution and a reasonable cost for the camera and related accessories. Disadvantages include delays and costs associated with processing, and the need to scan the picture into a computer if the researcher is interested in sharing images.
Analog (video) cameras offer a real-time visualization experience, but with several shortcomings in terms of ease of installation and use, image resolution, and picture quality. These cameras require the researcher to install a frame grabber into the computer to capture images. Choosing the proper device and installing it into the computer generally require some computer hardware expertise.
Digital cameras designed for microscopy capture high-resolution still images that can be added to reports or e-mailed to colleagues to share research. Coupled with a software package designed for photomicrography, one can edit and enhance the images in real time. A few of these systems can also be used off of the microscope for other imaging applications.
A recent development is the digital video camera, which combines the benefits of a digital camera with those of an analog video camera. With one system, the digital video camera allows researchers to capture high-resolution still images along with continuous video streams and time-lapse sequences without requiring the installation of a frame grabber. These features allow researchers to incorporate digital multimedia into work instructions, training materials/videos, and as documentation for inclusion in reports and e-mails.
One such system is the Microscopy Documentation System 100 (MDS 100) from Eastman Kodak Company, Molecular Imaging Systems. Relative to analog video cameras, the MDS 100 system offers an improvement in image quality, a reduction in cost, and the convenience of not having to install a frame grabber in the computer.
The system works equally well under most microscopy illumination conditions, including brightfield transmitted and reflected light, darkfield transmitted and reflected light, polarized light, phase contrast, and Nomarski illumination conditions.
Researchers at the Torrington Co. (Torrington, CT) use the system to document the condition of parts sent to the engineering department for evaluation. The parts include products manufactured by the company, its suppliers, as well as matting components from its customers. Images are used to document weld integrity, fatigue, and the wear of bearings due to misalignment or inadequate lubrication.
The camera's ease of use allows the company's receiving engineer to completely document the post-test evaluation without requiring a significant amount of photographic experience. The ability to send these images electronically means that all interested parties can discuss the issues as early as possible. Action plans can be formulated without the delay time associated with regular mail. This permits the company to resolve development issues and launch product programs in less time. The company's existing video imaging system did not have the resolution of the MDS 100 system.
System Benefits
The product comprises the MDS 100 camera, a lens, and proprietary MDS 100 software. A principal benefit of this imaging solution is the ability to digitally acquire images from standard light microscopes (including stereo microscopes) from all major manufacturers by attaching the camera to either a C-mount, or, with the included lens, to the majority of microscope eye-pieces. Once mounted, the camera and software allow the researcher to accurately capture and reproduce color or convert images to gray scale. Off of the microscope, this lens can be used to focus on specimens as close as 1/4 in. from the front of the camera, to infinity.
The camera utilizes a Kodak-manufactured progressive scan CCD (charge-coupled device) with square pixels delivering 640 × 480 pixel resolution in 24-bit color. The camera communicates through the USB connection and is capable of displaying live, color images at up to 30 frames per second onto a PC monitor. The real-time capability allows users to quickly and easily focus the full field of view. The camera also features a 2× digital zoom that is useful for photomicrography and macro photography. For macro photography, the compact camera easily fits into the palm of the hand for easy, handheld operation, or can be attached to a tripod or copystand with its standard tripod mount.
The USB connection allows digital video streams to be captured at a resolution comparable to analog video solutions, or digital still images can be captured at resolutions of up to 1.2 million pixels (1280 × 960). The camera provides full, uncompressed image data to the computer in seconds. The host computer powers the camera, eliminating the need for additional power supplies or wires.
Software
The software package running on a PC (Windows 98 or Windows 95 OSR 2.1, Microsoft Corp., Redmond, WA) controls the MDS 100 camera. The software offers a combination of dynamic video imaging, time-lapse photography, voiceover, and digital still imaging. Researchers can optimize image sharpness, brightness, or contrast in real time. White balance and exposure times can be set to automatic mode or can be adjusted manually with the results depicted in real time on the imaging preview screen. After the image is captured, the software allows users to edit and enhance their images with a variety of filters to sharpen, adjust color, contrast, and correct the gamma.
Conclusion
The MDS 100 system offers researchers a digital alternative to a film or analog video imaging system. The result is a fast and cost-effective way to put qualitative still and video image data into a computer and incorporate these data into work instructions, e-mail, and reports to customers.
Mr. Borrelli is Microscopy Marketing Manager, and Mr. Neiss is Microscopy Commercialization Manager, Eastman Kodak Co., 4 Science Park, New Haven, CT 06511, U.S.A.; tel.: 203- 786-5606; fax: 203-624-3143; e-mail: Aborrel@kodak.com.