Switch to English Language Passer en langue franšaise Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 74,515   Posts: 1,645,432   Online: 1198
      
Page 2 of 2 FirstFirst 12
Results 11 to 12 of 12
  1. #11
    bowzart's Avatar
    Join Date
    May 2008
    Location
    Anacortes, WA
    Shooter
    Multi Format
    Posts
    1,219
    Images
    15
    Well, good luck. My understanding is that about 150░ is pretty much the limit and even that is questionably practical.

    My thought is that if you view a circle from the front dead center, it appears to be a circle. As you tilt it so you are no longer looking at it on axis, it becomes less circular, and the more you tilt it the greater the ratio of the length of the ellipse to its width becomes. As this becomes very extreme, the ellipse becomes more like a straight line to the eye and less like a two dimensional shape. At 180░, you'd be looking at the edge of the plane the circle is inscribed upon, and you wouldn't even see the circle at all!!

    Additionally, there are two other factors in play here. First, as the view from points on the image plane get farther from the axis, the difference between the axial circle and the off - axial ellipse represents "lost" light. The hole is actually getting smaller (in its area) in relation to the image plane. And of course, the distance from pinhole to film becomes progressively much greater with that extreme geometry. Remember that the intensity of the light varies inversely to the square of the distance from the source. So the light fall off will be extreme, and probably, regardless of the amazing feat of getting a great wide angle, would be impractical.

    Unless you get the making of the pinhole down to where the material is extremely thin, you are making a tube, which further limits your ability to achieve a wide angle. One reason I like the idea of using a front surface mirror is that the material deposited on the surface can be far thinner than any piece of metal you could possibly use.

  2. #12
    q_x
    q_x is offline
    q_x's Avatar
    Join Date
    Jun 2008
    Location
    Poland
    Shooter
    Pinhole
    Posts
    166
    Yes, of course you're right. I'm trying 160 degrees camera now and 150 deg is maximum.
    As I said - this is a milestone in construction of wide-angled pinhole cameras. Not half as brilliant, as the others. And it needs polishing. It needs mathematic instrument (or software) I don't have, to make it better. I'm (probably) a nerdy artist, not artistic nerd.
    However - I've checked the maths - it seems this construction should work. As far as 1) the plate is very thin and 2) the cap is very close to the pinhole .
    With all my heart in this project, I will not put any glass between the film and rest of the world. This is the dogma for me.
    But others can do it

    As I said - I will post my first solarigraphy with some comments after Christmas Eve.

    Cheers,
    Luke
    Use the Force, Luke!

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  Ś   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin