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Thread: Optical Problem

  1. #1 Optical Problem 
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    Its a known fact that concave mirror forms only virtual images that cant be caught on a screen. But yet we can see the image on the screen (eye) when we look through the mirror. Hows that?????
    Thanx for your help!


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  3. #2  
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    The Hubble telescope is a reflecting telescope, and we have all seen photos taken by the Hubble. So, what are you talking about?


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  4. #3  
    Moderator Moderator Dishmaster's Avatar
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    I can't understand this either. Any reflective telescope uses concave mirrors. They can be operated in their prime focus, where the real image is projected onto a detector (c.f. Schmidt camera).
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  5. #4  
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    Sorry my mistake....Its not actually about telescopes the thing is that virtual images cannot be caught on a screen. But when a CONVEX not CONCAVE mirror forms virtual images and we see through it does form an image on our retina or the eye. Thats my doubt!

    Sorry again!!
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  6. #5  
    Forum Ph.D. Leszek Luchowski's Avatar
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    If you see anything at all, it's because an image is produced on your retina.

    Any mirror (flat, convex OR concave) can produce a virtual image. Then you look at it (at the virtual image that is), and the lens of your eye produces a real image of it (yes, a real image of the virtual image) on your retina.

    That's what happens when you look in a good old plain mirror while combing your hair.

    A convex mirror can also produce a real image, i.e. project an image onto a screen, or an image sensor, or a photographic film.

    For a hands-on experience, get a magnifying (concave) mirror. You can easily buy one slightly bigger than a CD, or a smaller pocket version, at your local store of beauty products. Have some fun looking into it (at yourself and objects far and near; also, hold the mirror close or far away from your eye) and making it reflect light onto walls.

    PS: you can also easily get a small convex mirror; they are sold as "blind spot removers" for side rearview mirrors on cars. But they are less fun because they won't project a real image onto anything.

    Enjoy, and benefit scientifically.
    Leszek. Pronounced [LEH-sheck]. The wondering Slav.
    History teaches us that we don't learn from history.
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  7. #6  
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    The convex mirror causes the rays of light to diverge, but the lens of your eye focuses them and forms the image. Does that answer the question?
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  8. #7  
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    Yes sir!! That does answer the question. Thanks.
    Thanks A Lot!!
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