Results 1 to 9 of 9
  1. #1
    Platinum Lounger
    Join Date
    Feb 2001
    Location
    Yilgarn region of Toronto, Ontario
    Posts
    5,453
    Thanks
    0
    Thanked 0 Times in 0 Posts

    pinhole camera made from a drink can

    Astronomy Picture of the Day
    ""If every picture tells a story, this one might make a novel. The six month long exposure compresses the time from December 17, 2007 to June 21, 2008 into a single point of view. Dubbed a solargraph, the remarkable image was recorded with a simple pinhole camera made from a drink can lined with a piece of photographic paper. The Clifton Suspension Bridge over the Avon River Gorge in Bristol, UK emerges from the foreground, but rising and setting each day the Sun arcs overhead, tracing a glowing path through the sky. Cloud cover causes dark gaps in the daily Sun trails. In December, the Sun trails begin lower down and are short, corresponding to a time near the northern hemisphere's winter solstice date. They grow longer and climb higher in the sky as the June 21st summer solstice approaches.""
    Attached Images Attached Images

  2. #2
    Silver Lounger
    Join Date
    Jul 2001
    Location
    Ottawa, Ontario, Canada
    Posts
    1,609
    Thanks
    0
    Thanked 1 Time in 1 Post

    Re: pinhole camera made from a drink can

    <img src=/S/confused3.gif border=0 alt=confused3 width=45 height=45> Ok you astronomers (amateur and otherwise), help me to understand why the slope of the sun's apparent trajectory starts/ends at a virtual point on the left but is spread across a significant portion of the right horizon.
    Regards
    Don

  3. #3
    Platinum Lounger
    Join Date
    Feb 2001
    Location
    Yilgarn region of Toronto, Ontario
    Posts
    5,453
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: pinhole camera made from a drink can

    <P ID="edit" class=small>(Edited by chrisgreaves on 19-Jan-09 06:42. added link to Analemma Over the Porch of Maidens )</P>>a virtual point
    Good point.
    It's virtual.
    Inspect, instead, the RHS.
    Obviously all depends on the range of view.
    If you go to the original site/image you'll see that the RHS is truncated by a tree.
    To see the effect of viewpoint, place your left hand palm facing the screen at the LHS of the image, and gradually slide your hand to the right (collecting dust, cat hairs etc).
    Now imagine that in place of your hand, the camera had been oriented a bit towards the right; you'd get the same effect.
    Now imagine what would happen ('what you would see?") if the camera's view at the RHS had been a bit more towards the left.
    Hope This helps.

    (later) You might like to inspect this image

  4. #4
    Silver Lounger
    Join Date
    Jul 2001
    Location
    Ottawa, Ontario, Canada
    Posts
    1,609
    Thanks
    0
    Thanked 1 Time in 1 Post

    Re: pinhole camera made from a drink can

    Thanks Chris
    Regards
    Don

  5. #5
    New Lounger
    Join Date
    Sep 2008
    Location
    Medway, Kent, United Kingdom
    Posts
    23
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: pinhole camera made from a drink can

    Chris

    I love this web site. I have it as my home page so It's the first thing to great me as I fire up the internet each day.

    Here is an Analemma over the Ukraine taken in the evening.

    Regards

    Graeme

  6. #6
    Platinum Lounger
    Join Date
    Feb 2001
    Location
    Yilgarn region of Toronto, Ontario
    Posts
    5,453
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: pinhole camera made from a drink can

    >I have it as my home page
    Oh. I haven't sunk to those depths*(grin!)
    It's part of my "Weekly Dose" which I "Open All in Tabs"

  7. #7
    New Lounger
    Join Date
    Sep 2008
    Location
    Medway, Kent, United Kingdom
    Posts
    23
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: pinhole camera made from a drink can

    How could you not when you get awe inspiring pictures like this and like this on your screen each morning!

    Regards

    Graeme

  8. #8
    Platinum Lounger
    Join Date
    Feb 2001
    Location
    Yilgarn region of Toronto, Ontario
    Posts
    5,453
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: pinhole camera made from a drink can

    >How could you not when you get awe inspiring pictures like this and like this on your screen each morning!

    Because I've got this (<post:=753,548>post 753,548</post:>) in my life each morning!

  9. #9
    New Lounger
    Join Date
    Sep 2008
    Location
    Medway, Kent, United Kingdom
    Posts
    23
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Re: pinhole camera made from a drink can

    Is that the fine feline you call Jupiter ? Or is it Saturn ?

    Regards

    Graeme

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •