training for advanced research


Glossary terms about Brightness

Referring to the appearance of an image: the extent to which all parts of an image emit or reflect light. An image with very low brightness may appear black.

12 pages mention Brightness

Beam Adjustment
Choose a low magnification to start with and ensure your contrast and brightness are adjusted so you can see an image. 
Concepts - introduction
The intensity of brightness on the screen is in proportion to the number of electrons originally produced. 
Electron column
By amplifying and modulating the brightness of the detected electron signals an image is produced. 
Electron gun
Thermionic gun Field emission gun Emission Thermionic Field Emission W LaB6 FE Size (nm) 1 x 105 2 x 104 0.2 brightness (A/cm2. 
Generating an image
It is, however, not the only factor that contributes to the contrast and brightness in an SEM. 
Image Capture
To take a photograph you may need to adjust the contrast and brightness against a scale inbuilt in the machine, otherwise you can rely on your eyes. 
Introduction - aims and learning outcomes
Perfecting an image - signal processing
In this way we can adjust the signal to change contrast and brightness of our final image. 
Sample preparation
Saturating the filament
The relationship can be seen in a graph of filament current against electron emission (or brightness). 
Scan rate and signal to noise ratios
Noise pulses are derived from such sources as beam brightness, condenser lens settings (spot size), and SE detector ‘gain’, and may impart a salt-and-pepper (grainy) appearance to the image. 
The electron gun
This will produce a poor quality image because the brightness will vary across the image.