Projection Geometry

Question 1

sharpness definition

Answer 1

measures how well a boundary between two areas of deferring radiodensity is revealed

Question 2

three ways to make sure sharpness is best it can be

Answer 2

1. use as small an effective focal spot as possible
2. increase the distance between the focal spot and the object by using a long, open-ended cylinder
3. minimize the distance between the object and image receptor

Question 3

spatial resolution is?

Answer 3

measures how well a radiogrpah is able to reveal small objects that are close together

Question 4

focal spot size we want to work with in dentistry

Answer 4

.4 mm

so we dont loose details - so best resolution as possible

Question 5

larger focal spot?

Answer 5

loose sharpness and cannot differentiate between different things

Question 6

what dimension beyond tooth do you want to achieve in a peri-apical picture?

Answer 6

atleast 2mm beyond apex of bone