Magnification through a lens at various diameters

In summary, when using a high power plus lens with a known front curve, index, and center thickness, and observing a known diameter circular target at a known distance behind the lens, the ratio between the diameter of the original target and the measured target as viewed through the lens can be used to calculate the lens's focal length and power. However, this ratio changes significantly when a larger target size is used, even though the lens power remains the same. This is known as radial distortion and can be compensated for using specific formulas.
  • #1
Ken Van Cleave
1
0
We have a high power plus lens of known front curve, index, and center thickness and have placed a known diameter circular target at a known distance behind the lens. Observing the circular target through the lens we compute the ratio between the diameter of the original circular target behind the lens and the measured target diameter as viewed through the lens on the other side.

Using a very small target, the focal length and power of the lens can be calculated fairly accurately using this magnification ratio along with the distance from the back of the lens to the target. The problem is that the ratio changes significantly when a larger target size is used even though the lens power is the same.

Why does this happen? Are there any formula(s) that can compensate for this so the power can still be predicted as accurately as when a very small target size is used?
 
Last edited:
Science news on Phys.org
  • #2

1. How does the diameter of a lens affect magnification?

The diameter of a lens directly affects magnification. A larger diameter lens allows more light to enter, resulting in a higher magnification. This is because a larger lens has a wider field of view and can capture more details.

2. What is the relationship between magnification and the focal length of a lens?

The focal length of a lens also plays a role in magnification. A shorter focal length lens will have a higher magnification compared to a longer focal length lens. This is because a shorter focal length lens bends light more, resulting in a larger image.

3. Can magnification be increased by adjusting the distance between the lens and the object?

Yes, the distance between the lens and the object can affect magnification. Increasing the distance will result in a larger image, while decreasing the distance will result in a smaller image. However, this will also affect the clarity and sharpness of the image, so it is important to find the right balance.

4. Is there a limit to how much magnification can be achieved through a lens?

Yes, there is a limit to how much magnification can be achieved through a lens. This limit is known as the resolution limit and is determined by the quality and design of the lens. Going beyond this limit will result in a blurry or distorted image.

5. How does the quality of a lens affect magnification?

The quality of a lens is crucial in achieving high magnification. A lens with better quality materials and construction will have less distortion and produce a clearer and sharper image. This ultimately leads to higher magnification and better overall results.

Similar threads

I How to Measure Magnification of a Lens System with Liquid Surface
    • Optics
2
Replies
40
Views
3K
I Lens angle of coverage/image circle
    • Optics
Replies
5
Views
1K
I Tilted plane wave through a 2 lens system
    • Optics
Replies
5
Views
1K
I Focusing UV light from a 275nm LED down to a small spot
    • Optics
Replies
10
Views
2K
I Factors that influence depth of field
    • Optics
2
Replies
41
Views
525
What are the key considerations for imaging with a condenser fresnel lens?
    • Optics
2
Replies
58
Views
5K
Question on Optical Systems and Lenses
    • Optics
Replies
1
Views
677
Calculate a radius of a circle on a screen
    • Introductory Physics Homework Help
Replies
3
Views
387
Finding the magnification of a ball lens
    • Introductory Physics Homework Help
Replies
4
Views
3K
Determining the light intensity in a double convex lens
    • Optics
Replies
7
Views
3K

Hot Threads

Recent Insights

Back
Top