n
Partial or imperfect shadow about the umbra, or true shadow, of an object. In radiography, it is influenced by the size of the focal spot, focal-film distance, and object-film distance. See also
geometric penumbra
| Dental Dictionary: geometric penumbra |
(pən-um′brə)
n
n
| 5min Related Video: geometric penumbra |
Learn More
 | geometric unsharpness |
| adumbration |
| geometry of x-ray beam |
 | What causes umbras and penumbras? Read answer... |
| Which is darker the umbra or penumbra? Read answer... |
| What is an umbra and penumbra and how do they relate to eclipses? Read answer... |
Help us answer these
 | What would happen if you stand in the penumbra? |
| When standing in the penumbra what eclipse will you see? |
| What is the part of the shadow that surrounds the penumbra? |
Post a question - any question - to the WikiAnswers community:
Copyrights:
 |
 | Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved. Read more |
Related answers
- What is a penumbra?
- What is penumbra?
- What is gemortic penumbra?
- What are the umbra and the penumbra?
- What is the meaning of penumbra?
ADVERTISEMENT
