Viewing Specimens in the SEM
1. Images that we see
The SEM has a monitor from which we as the operators view the specimen. The image is derived from the detection of excited electrons that are being bounced off the gold specimen at varying speeds and signals. The two detectors pick up the electron signals and via an analog-to-digitital conversion process the image is viewed on a computer monitor, captured on black and white negative film or stored as an image on the computer's hard-drive.
2. Black and white images
Electron microscopes can only be viewed in black and white. This is because the electrons that are detected do not have a colour spectrum like that of the incandescent light in light microscopes. The only way to colour the derived images is to generate artificial colour via a computer program or hand paint the negative.
Copyright © 2003, Australian Museum
