Aperture Stops, Entrance Pupils & Exit Pupils

  • Thread starter Thread starter toam
  • Start date Start date
Click For Summary
SUMMARY

The discussion centers on an optics assignment involving a lens with a diameter of 4cm and a focal length of 5cm, paired with an aperture of 5cm positioned 2cm in front of the lens. The user concludes that the lens acts as both the aperture stop and the entrance pupil, rendering the aperture redundant. This scenario is confirmed as acceptable, as supported by the text "Fundamentals of Optics" by Jenkins and White, which discusses front stops in optical systems.

PREREQUISITES
  • Understanding of optical components such as lenses and apertures
  • Familiarity with the concepts of entrance pupils and exit pupils
  • Knowledge of focal lengths and their implications in optics
  • Ability to interpret optical diagrams and systems
NEXT STEPS
  • Study the concept of aperture stops in detail using "Fundamentals of Optics" by Jenkins and White
  • Research the role of entrance and exit pupils in optical systems
  • Explore practical examples of optical systems without apertures
  • Learn about the implications of lens diameter and focal length on image formation
USEFUL FOR

Students in optics, optical engineers, and anyone studying the principles of light behavior in lenses and apertures.

toam
Messages
13
Reaction score
0
I'm doing an assignment involving an optics question.

There is a lens (diameter 4cm, focal length 5cm) an apeture (diameter 5cm, position 2cm in front of lens) and an object (1.5cm high, 8cm in front of lens).

Now I have determined that the lens is the aperture stop. Now, because the lens is the aperture stop the aperture does not limit the incoming light at all and this leads me to believe that the lens is the entrance pupil. Since the lens is the entrance pupil the lens must also be the exit pupil since it can't make an image of itself.

Is this an acceptable situation to have? I assume it is because it makes the aperture completely redundant and unnecessary and therefore is equivilent to the same system without an aperture, but I can't find any examples in books or lecture notes where this occurs...
 
Physics news on Phys.org
You are correct in your reasoning. See the section on Front Stops in "Fundamentals of Optics" by Jenkins and White.
 

Similar threads

How Do You Calculate the Numerical Aperture of This Optical System?
  • · Replies 10 ·
Replies
10
Views
5K
Find pupil locations w/ paraxial ray tracing (thick lens, Geary CH 5)
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Telecentric entrance pupil - Optics
  • · Replies 3 ·
Replies
3
Views
2K
Finding the Optimal Aperture Stop for a Portrait Photo
  • · Replies 1 ·
Replies
1
Views
2K
Stargazing Calculating the Resolving power of a Telescope
  • · Replies 7 ·
Replies
7
Views
4K
Numerical aperture of a Keplerian telescope
  • · Replies 1 ·
Replies
1
Views
3K
Graduate Diffraction and Aperture Size: How Does It Affect Image Resolution?
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Optics-maximum lens resolution and difraction limit
  • · Replies 19 ·
Replies
19
Views
10K
Focal Length problem for astronomy class
  • · Replies 3 ·
Replies
3
Views
4K
Stargazing What are the limitations of astrophotography and how can they be overcome?
  • · Replies 34 ·
2
Replies
34
Views
14K