Effect of distance in collimated space. NOT for homework.

In summary, the focal length of the three lenses in the optical setup affects the magnification of the image that is captured by the cell phone. The focal length of the first lens (the one with the focal length of 3) affects the magnification of the image that is captured by the cell phone by 8. The focal length of the second lens (the one with the focal length of 4.6 mm) affects the magnification of the image that is captured by the cell phone by 1. The focal length of the third lens (the one with the focal length of 30 mm) does not affect the magnification of the image that is captured by the cell phone.
  • #1
bdg2
3
0
Hi All,
I apologize in advance for the elementary nature of my question, but I have made a genuine effort to understand what is going on using a couple of optics textbooks and remain confused. My background is not in optics but I definitely am just missing something basic.

I have an optical set up I posted here: http://i.imgur.com/XUH0w.png . I am using a cell phone as my imaging device, shown on the far left of the diagram. It has a lens with focal length of 4.6 mm and I have set it to focus on infinity, so the lens and CMOS should be separated by a distance of 4.6 mm. I understand the system for the most part except for the distance I have labeled d4 and similarly the distance I have labeled d1. d1 I basically make as small as possible -- I have an aspheric lens pressed right about against my cell phone and I'm not planning on changing that distance. However, I'm not understanding the effect of measurement d4 on the system's overall magnification. The linear magnification I get from the combination of the first two lenses, or at least what I thought it was, was just (focal length lens 3)/(focal length lens 4), or about 8. However, I notice in my system that the distance d4 changes the image I capture. If I have distance d4 very small, I can fill my cmos sensor with the image of my intended object (my object is actually an image coming out of a fiber bundle).

Anyway, can someone help me to understand the effect on the systems magnification of the distance in collimated space between my "objective" (aspheric lens) and "tube lens" (30 mm achromatic lens). Thanks and again apologies for asking such a rudimentary question.
 
Physics news on Phys.org
  • #2
I would not expect any influence from d4. The light is parallel and nothing changes with distance, neglecting possible nonlinear effects in your setup.
 
  • #3
Yeah that's what I would expect too. It's causing quite a big difference, so I must be doing something wrong in setting it up. Thanks
 

1. How does distance affect collimation in space?

The effect of distance on collimation in space is that as distance increases, the collimated beam becomes less focused and more divergent. This is due to the principle of geometric optics, where light rays spread out as they travel further away from the source.

2. What is the relationship between distance and collimation in space?

The relationship between distance and collimation in space is an inverse one. As distance increases, collimation decreases and the beam becomes wider. This can be seen in the formula for calculating beam divergence, where a larger distance results in a smaller beam waist and larger divergence angle.

3. How does the size of the collimated beam change with distance in space?

The size of the collimated beam increases with distance in space. This is because as the beam travels further, it spreads out and becomes wider, resulting in a larger beam diameter. This can be seen in the formula for calculating beam divergence, where distance is a key factor in determining the size of the beam waist.

4. Can collimation be maintained over long distances in space?

Collimation can be maintained over long distances in space, but it requires precise and careful alignment of the collimation optics. Any slight misalignment or disturbances in the medium can cause the beam to diverge and lose its collimation. In addition, using advanced techniques such as active or adaptive optics can help maintain collimation over longer distances.

5. How does distance affect the accuracy of measurements using collimated beams in space?

The accuracy of measurements using collimated beams in space can be affected by distance, as the beam may become wider and less focused. This can result in a larger beam waist and therefore, a larger spot size on the target, making it more difficult to accurately measure small or precise features. It is important to consider the distance when using collimated beams for measurements in space and make any necessary adjustments for accurate results.

Similar threads

Can Math Model Real-World Camera Focusing Dynamics?
    • Mechanics
Replies
1
Views
954
I Using simple lenses to image AFM Probes
    • Optics
Replies
10
Views
1K
I Collimating a fibre-coupled LED light source
    • Optics
Replies
1
Views
1K
I Lens Calculations to Focus Light
    • Optics
Replies
10
Views
941
I Tilted plane wave through a 2 lens system
    • Optics
Replies
5
Views
1K
I Difference between Working distance and object distance
    • Optics
Replies
1
Views
1K
Calculate a radius of a circle on a screen
    • Introductory Physics Homework Help
Replies
3
Views
387
I How to make the best collimator using a system of lenses?
    • Optics
Replies
4
Views
898
I Finding focal length of the lens using "u-v" method
    • Optics
Replies
8
Views
2K
I Collimating an extended source to infinity?
    • Other Physics Topics
Replies
5
Views
20K

Hot Threads

Recent Insights

Back
Top