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optical illusions, blind spots and moon size

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  • optical illusions, blind spots and moon size

    Stumbled over this site, found it interesting to read:
    http://www.vision1to1.com/EN/HomePag...26&Article=134


    But isn't there a better explanation of this:
    Why does the moon look bigger at the horizon than it does when overhead?

    Obviously, the moon’s size doesn’t change. When the moon is close to the horizon, experts explain, it is nearer to familiar objects, such as mountains or skyscrapers. The brain erroneously interprets this information and makes the moon appear larger than it really is. Without the benefit of surrounding objects, the moon seems to decrease in size as it climbs through the night sky.


    Rakido
    "Women don't want to hear a man's opinion, they just want to hear their opinion in a deeper voice."


  • #2
    No - its actually quite correct.

    It also accounts for the often heard comment by women that "your appendage is too small" - they can compare it with the size of your gut that they can see. You on the other hand can never see both at the same time so erroneously(?) are of the opinion that it is in fact quite big.
    Lawrence

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    • #3
      I always put that down to atmospheric lensing

      Also it does vary it's distance from us so sometimes it is bigger.

      Comment


      • #4
        It may vary its distance as it orbits the earth, but the change in the observed size (diameter) when viewed from earth because of that factor is most likely 0.00000000000000001 of an inch and hardly detectable by the naked eye.
        Lawrence

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        • #5
          Exactly.

          Also, when you form a tube with your hand and look through it at the moon, it appears smaller, because you have no reference points, and your brain cannot measure or guess the distance correctly.

          This also means that you won't be able to make a photograph of that nice big moon - it'll always be small on the photo.

          AZ
          There's an Opera in my macbook.

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          • #6
            found this site, but beware, that's a looong read (not yet finished)

            http://www.lhup.edu/~dsimanek/3d/moonillu.htm


            Rakido
            "Women don't want to hear a man's opinion, they just want to hear their opinion in a deeper voice."

            Comment


            • #7
              Originally posted by az
              This also means that you won't be able to make a photograph of that nice big moon - it'll always be small on the photo.
              Zoom lens, anyone ?
              Nah, I know what you mean... Too bad though...

              Does this effect also occur when someone asks: does my a$$ look fat in this skirt ?

              Back on topic: interesting reads, Rakido!

              Jörg
              pixar
              Dream as if you'll live forever. Live as if you'll die tomorrow. (James Dean)

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              • #8
                VJ
                Does this effect also occur when someone asks: does my a$$ look fat in this skirt ?
                As an expert in this area (I have been married for too long! ) I can tell you with authority that the answer is always NO - it just makes the skirt look smaller for said large reference to compare too.
                Lawrence

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                • #9
                  My wife is tiny, so at least I never face that question.

                  But oh how I fear the post hair dresser questions
                  Juu nin to iro


                  English doesn't borrow from other languages. It follows them down dark alleys, knocks them over, and goes through their pockets for loose grammar.

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                  • #10
                    Originally posted by az

                    ...
                    This also means that you won't be able to make a photograph of that nice big moon - it'll always be small on the photo.

                    AZ
                    Nah, as VJ almost said, it can be done (just with one little trick)...

                    Somebody wants you to make picture of him with big moon behind? No problem, take lenses with the biggest focal that you have, go in the opposite direction to the moon and when you'll be in the distance when that somebody will be in "natural" size on the photo, the moon will be big for shure

                    Only one eventual difficulty to overcome now - weak illumination. But that's something to resolve if you really want to

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                    • #11
                      I'm not convinced that using the perspective difference when moving further back and applying a zoom lens will yield an effect as dramatic as can sometimes be seen in reality...

                      Still, it could be as close as one could get...


                      Jörg
                      pixar
                      Dream as if you'll live forever. Live as if you'll die tomorrow. (James Dean)

                      Comment


                      • #12
                        Very close...





                        And those are only first two photos for moon big google image search that shows rather good what you can do just with proper lenses.

                        edit: and of course it wouldn't be as dramatic. But what photo of some natural phenomena is as dramatic as the phenomena itself?
                        Last edited by Nowhere; 8 August 2003, 13:58.

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                        • #13
                          cking4

                          You should have noticed that the correct answer is ONLY the word NO - not with any explanation attached - I explained only for the benefit of those unmarried souls that must still figure out why the question needs an answer.
                          Lawrence

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                          • #14
                            Originally posted by LvR
                            cking4

                            You should have noticed that the correct answer is ONLY the word NO - not with any explanation attached - I explained only for the benefit of those unmarried souls that must still figure out why the question needs an answer.
                            Is that a "No, not if I have a skyline-reference ?"

                            Isn't it more than just "no": you shouldn't even think about the answer ! Once you think about the question, she won't believe the "no"....


                            Jörg
                            (an unmarried soul )
                            pixar
                            Dream as if you'll live forever. Live as if you'll die tomorrow. (James Dean)

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                            • #15
                              Never, never, EVER compare any womens ASS with a skyline, or you are going to stay an unmarried soul for a very long time.
                              Lawrence

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