Pinhole glasses

Discussion in 'General Science & Technology' started by SoLiDUS, Jan 4, 2003.

  1. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    Please read my posts, and then quote what I have said that you find in error.
     
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  3. Yazata Valued Senior Member

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    When I use the pinhole glasses effect, I don't perceive the world through the hole as being inverted or reversed laterally. It looks normal, just dimmer and in better focus.
     
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  5. exchemist Valued Senior Member

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    Exactly.
     
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  7. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    Somehow I think you mean that to be a response to my request?
     
  8. exchemist Valued Senior Member

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    Is that a question or a statement?
     
  9. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    For the record, in post #25 I responded to Tritus's post #24, and answered his question:
    In post #30 I responded to Sculptor, relating my story of viewing the eclipse of the sun inside a box with a pinhole in one side, and mentioned that the image of the eclipse was reversed. I then questioned his statement about the image of the wall clock being reversed when viewed through his card with a pinhole, saying "interesting, I didn't know that would appear reversed". He quickly corrected himself, saying:
    Anyone who followed my part of the conversation knows what I have said, and knows that I do understand about how the brain puts the inverted image that is projected on the retina into the right spatial perspective. I also understand the effect of directly viewing the world through a pin hole, and the advantages there are in resolution. I didn't say images were seen reversed and upside down when viewed through a pinhole, and I did correct Sculptor when he said that.
     
  10. sculptor Valued Senior Member

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    your:
    seems to have confused me
     
  11. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    But not for long. You corrected yourself.
     
  12. sculptor Valued Senior Member

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    and here, I had thought that I was correcting you.
     
  13. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    Thank you for that.
     
  14. sculptor Valued Senior Member

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    my pleasure
     
  15. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    Anyway, I received the pinhole glasses. They do as expected. I found that after testing them for about two hours one evening, I could function pretty well with them and without my glasses, and I felt a relaxed sensation, like normal vision was somewhat stressful on the eyes, and the pinhole glasses releaved some of that. Wearing them to drive would be dangerous though, and even walking around is a little disorienting. Reading goes much slower but there is sharp vision without my glasses.
     
  16. sculptor Valued Senior Member

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    Would the size of the "pin holes" adjust the focal length?
     
  17. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    It might, but focus wasn't a problem really. You end up looking through a different hole with each eye, so bigger holes would make it easier to navigate with them, I think. I could do some destructive testing, lol.
     
  18. DaveC426913 Valued Senior Member

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    It will affect the depth of field.

    The smaller the holes, the bigger the DoF: with arbitrarily small holes, your DoF would go from arbitrarily near zero distance to infinity (in the same scene) - which would be off the bottom of this chart:

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    Unfortunately, it does so at the expense of brightness. Which is why any kind of imaging is always a compromise.
     
    Last edited: Jul 25, 2016
  19. DaveC426913 Valued Senior Member

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    You seem to be claiming that, when looking through a pinhole, one sees an inverted image. Correct me if I'm on what you're saying.

    If I'm correct, it is an erroneous observation/conclusion.

    When one looks through a pinhole aperature, one does not see in inverted image.

    In post #34 I posted an image of how you can make a pinhole just with your hand. If you try that right now, you will see that the image is not inverted.

    Let's start with that, and work our way back toward pinhole cameras - which have a plane of imaging, and which do invert the image.
     
  20. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    Show me where I claim that. Notice the post about viewing the eclipse. Are you familiar with the technique. The image comes through a hole on one side of the box, and projects an image reversed on the other side which acts as a screen.
     
  21. DaveC426913 Valued Senior Member

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    I'm not asserting that you claim that; that's why I asked you to correct me.

    It's not easy to tell exactly what is being claimed (by you or by others) because the thread - which is, first and foremost, about pinhole glasses - is getting confounded by discussion about ocular inversion and pinhole cameras, which are a different animal, yet have been used in the same paragraph:

    It's a bit vague about whether "naked eye" implies "using pinhole glasses", but it does seem to read that way to me. And, apparently exchemist, who stepped in to correct it.

    So I'm not sure we're all agreed yet that pinhole glasses do not invert the image one sees.
     
    Last edited: Jul 25, 2016
  22. quantum_wave Contemplating the "as yet" unknown Valued Senior Member

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    That post was in reply to post #29. See if you see why I said what I said. I was challenging a statement about the clock being reversed, knowing he was wrong. He realized my point and corrected it.
     
  23. DaveC426913 Valued Senior Member

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    You mean post scultpor's #29 has been corrected? OK.
    So your post wasn't asserting that the image is inverted; you took his word for it? I didn't see where you challenged him though. (I may still be wrong.)
    But exchemist corrected it, assuming you were asserting it in post #30. I guess you sortta got caught in the middle there.

    Anyway, it's water under the bridge. No harm no foul.

    As long as everyone (including future readers) is in agreement on the corrected facts.
     
    sculptor likes this.

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