Lens & Focal Point System: Image Formation

[Gear2d]

Homework Statement

I have a two lens system (both are convex lens; converging lens). Say I set lens 1 on left hand side and lens 2 on the right hand side.

A)If I place an object within the focal point of lens 1 and the image create by this lens is OUTside the focal distance of lens 2, what type of image will be formed?


B) Now the same as part "A" but this time the image formed by lens 1 is inside the focal distance of lens 2, what type of image is formed?

Homework Equations

The Attempt at a Solution

A) Lens 1 will form a virtual upright image (since object is in the focal point of lens 1). Now this image becomes the "oject" of lens 2. Since it falls outside lens 2's focal distance the image formed will be real and inverted?

B) Same as Part "A" up until we get to lens 2. Now this time its in the focal distance of lens 2, so the object, which is virtual upright, will become real and upright?

 

[alphysicist]

Hi Gear2d,

Homework Statement

I have a two lens system (both are convex lens; converging lens). Say I set lens 1 on left hand side and lens 2 on the right hand side.

A)If I place an object within the focal point of lens 1 and the image create by this lens is OUTside the focal distance of lens 2, what type of image will be formed?


B) Now the same as part "A" but this time the image formed by lens 1 is inside the focal distance of lens 2, what type of image is formed?

Homework Equations

The Attempt at a Solution

A) Lens 1 will form a virtual upright image (since object is in the focal point of lens 1). Now this image becomes the "oject" of lens 2. Since it falls outside lens 2's focal distance the image formed will be real and inverted?

That sounds right to me.

B) Same as Part "A" up until we get to lens 2. Now this time its in the focal distance of lens 2, so the object, which is virtual upright, will become real and upright?

What is your reasoning for this result?

 

[baba89]

I would first like to clarify that the focal point of a lens is a point where parallel rays of light converge after passing through the lens. The focal distance is the distance between the lens and the focal point.

Now, for part A, you are correct in saying that lens 1 will form a virtual upright image since the object is placed within its focal point. However, when this image becomes the object for lens 2, it will form a real inverted image since it falls outside the focal distance of lens 2. This is because the rays of light from the virtual image will converge and then diverge again after passing through lens 2, resulting in an inverted image.

For part B, the object formed by lens 1 will still be virtual and upright. When this image becomes the object for lens 2, it will form a real upright image since it falls within the focal distance of lens 2. This is because the rays of light from the virtual image will continue to converge and form a real image after passing through lens 2.

In both cases, the final image will be inverted or upright depending on whether it falls outside or within the focal distance of lens 2. This is due to the nature of convex lenses, which cause light rays to converge and form an inverted image. I hope this helps clarify the image formation process in a two lens system.