Density of radiograph is affected by all, except:
mA
kVp
Cone angulation
Thickness of object
Images should have optimal density and contrast to facilitate interpretation. Although milliamperage (mA), peak kilovoltage (kVp), and exposure time are crucial parameters influencing density and contrast, faulty processing can adversely affect the quality of a properly exposed radiograph.
White and Pharoah, 7th ed, pg-91