Is a Flat Mirror Capable of Producing a Real Image?

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Discussion Overview

The discussion centers around the capability of a flat mirror to produce a real image, particularly in the context of a projector system. Participants explore the definitions of real and virtual images, the role of mirrors in image formation, and the implications of using a flat mirror in a projection setup.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant suggests that a projector can produce a real image using a flat mirror, questioning the definitions that state flat mirrors cannot create real images.
  • Another participant asserts that a flat mirror cannot produce a real image without additional elements, such as a curved mirror or a pinhole.
  • Some participants argue that when viewing an image projected onto a screen, it is considered a real image, regardless of the mirror's involvement.
  • A participant clarifies that the lens in the projector is responsible for producing the image, while the mirror merely redirects the light.
  • One participant challenges the definitions of real and virtual images, stating that the relationship does not fundamentally depend on the presence of mirrors.

Areas of Agreement / Disagreement

Participants express disagreement regarding the role of flat mirrors in producing real images, with some maintaining that flat mirrors cannot create real images, while others argue that the projection setup allows for real images to be viewed on a screen.

Contextual Notes

Definitions of real and virtual images are debated, and the discussion reflects varying interpretations of how mirrors affect image formation. There is uncertainty regarding the conditions under which a flat mirror may or may not contribute to the creation of real images.

Kevin Willis
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I am struggling on one concept that I can't find when doing a thorough search.

System: You have a projector (known to project real images onto a screen). The projector expands light with a lens, the light propagates to a flat mirror on a wall and reflects onto a screen.Conclusion: Although the image may appear distorted, it is real. It originated from a point and expanded before reflecting onto a screen.So, if that conclusion is right, then how is it that a flat mirror can be used a system that produces a real image when every definition basically says "no flat mirrors in a real image system"?

If the conclusion is wrong and in the system here the image is now virtual, then should I conclude that anything reflected off a flat mirror is virtual? Also, does this mean that a laser shining on a screen is real but a laser shining off a flat mirror on a screen is virtual (same concept, but just double checking)?
 
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It can't. Either the mirror is curved, or there is a pinhole you left out.
 
When you look through a mirror, you see a virtual image. You aren't looking through a mirror in this setup. You are looking at a screen. Any time you look at an image projected onto a screen, you are looking at a real image.
 
K^2 said:
When you look through a mirror, you see a virtual image. You aren't looking through a mirror in this setup. You are looking at a screen. Any time you look at an image projected onto a screen, you are looking at a real image.

Thanks, I think I understand the concept completely now.
 
In your projector, the lens produces the image. The mirror simply redirects the light so the image appears in a different location than it otherwise would. If you remove the mirror, and maybe cut a hole in the projector, you can probably get an image somewhere, maybe on the ceiling or on a different wall.
 
Kevin Willis said:
So, if that conclusion is right, then how is it that a flat mirror can be used a system that produces a real image when every definition basically says "no flat mirrors in a real image system"?

This was where you went wrong. I have never read this in any textbook. The connection between real / virtual has nothing, fundamentally, to do with mirrors or no mirrors.
 

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