1
Q
Factors influencing exposure (9)
A
Region of image Spp. And size FFD Film-screen type Use of grid Voltage Current Exposure time
2
Q
Define focal film distance
A
Total distance between focal spot and film
Should be kept constant (75cm)
3
Q
How does FFD affect exposure
A
Intensity of primary beam falls with increasing distance
Large FFD leads to under-exposure
Shorter FFD leads to over-exposure
