Negative lens imaging

Question 1

negative lens

Answer 1

always minified, always erect

Question 2

rule 1 of negative lens

Answer 2

ray parallel to the optical axis after the lens ‘diverges’; its path is as if it originated from the focal point F’

Question 3

rule 2 of negative lens

Answer 3

ray ‘targeting’ the focal point F 9focal ray), after the lens becomes parallel to the optical axis

Question 4

rule 3 of negative lens

Answer 4

ray crossing the center of the lens (nodal ray) does not change path, and continues after the lens the same path with the same tilit

Question 5

Lens focal leng F=-25cm, what is the power?

Answer 5

-4D

Question 6

If the beams are collimated before the lens…

Answer 6

Xo=0D

Question 7

Object located 50mm in front of a lens, object beam vergence is

Answer 7

-20D

Question 8

negative lens, for any object location

Answer 8

• the image is virtual, upright (M>0), located in the object space
• magnification is always less than unity (M

Question 9

object is located distance f in front of a plus lens of a focal distance f. object beam vergence is..

Answer 9

-P

Question 10

optical infinity

Answer 10

• object or image ray bundle is collimated
• object or image may be far away
• the corresponding ray bundle may be collimated by an optical element