Sony Alpha 100 DSLR snapshot at night - Venus and Moon

Discussion in 'Sony' started by FlintStone, Apr 21, 2007.


  1. It's not often you get the Ballad of Sir Patrick Spens quoted in a
    photographic NG :)

    David
     
    David Kilpatrick, Apr 24, 2007
    #21
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  2. FlintStone

    RichA Guest

    Thanks.
    1000mm f8 with an Olympus E-1 DSLR. 2000mm equivalent.
    The trick with the Moon is to use as large a telephoto as you've got
    (max 2000mm with a 35mm format which just fits it into the frame)
    and to shoot on a night when the stars don't twinkle. This indicates
    the "seeing" is steady and the pictures will be sharper.
     
    RichA, Apr 24, 2007
    #22
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  3. FlintStone

    Alan Browne Guest

    The above is correct IMO insomuch as compared to RichA's 1.7 stop
    overexposure.

    For a 1/4 moon, the exposure is no different than 1/1.
     
    Alan Browne, Apr 25, 2007
    #23
  4. FlintStone

    M-M Guest


    It depends on what you are exposing for. If you want to expose for the
    shadows at the terminator you will have to blow out the round side.

    True though, a quarter moon in general would be exposed the same as a
    full moon, all other things being equal. But the poster was referring to
    a "slim sliver" which is always close to the horizon and would require a
    longer exposure also because much less of it is bright.

    A small crescent can never be high in the sky at night.
     
    M-M, Apr 25, 2007
    #24
  5. FlintStone

    Alan Browne Guest

    http://www.pbase.com/flintstonestudio/image/77432804

    Is only a hair less than 1/4 moon.
     
    Alan Browne, Apr 25, 2007
    #25
  6. FlintStone

    M-M Guest

    http://www.pbase.com/flintstonestudio/image/77432804

    Is only a hair less than 1/4 moon.[/QUOTE]


    ARE YOU KIDDING ME?

    The moon in that photo was 1 or 2 days old. A quarter moon is 7 days
    old. That moon is very close to new.

    Maybe it looks like a quarter since the "sliver" is way overexposed.
     
    M-M, Apr 25, 2007
    #26
  7. FlintStone

    Alan Browne Guest



    ARE YOU KIDDING ME?

    The moon in that photo was 1 or 2 days old. A quarter moon is 7 days
    old. That moon is very close to new.

    Maybe it looks like a quarter since the "sliver" is way overexposed.[/QUOTE]

    That moon is about 1/5 at least.
     
    Alan Browne, Apr 25, 2007
    #27
  8. FlintStone

    Alan Browne Guest

    Okay, I take that back. It is really overblown making it look like more
    than it is.
     
    Alan Browne, Apr 25, 2007
    #28
  9. FlintStone

    FlintStone Guest

    That's right... I took about a dozen photos then, and that one had the best
    exposure of the dark part of the moon. I didn't realize it was Earths light but
    of course it has to be, since there is no atmosphere!
     
    FlintStone, Apr 25, 2007
    #29
  10. FlintStone

    M-M Guest


    It's 2 days old. 1/15th. It was taken on April 19 and the new moon was
    April 17.
     
    M-M, Apr 25, 2007
    #30
  11. FlintStone

    Jeff R. Guest

    Jeff R., Apr 25, 2007
    #31
  12. Roger-

    I think you said it, but I'm not sure! I understood the full moon's
    surface has an effect of retro-reflection, when light is reflected more
    strongly back along the path from which it originates.

    You mention your head's halo. An amateur pilot told me there was a
    similar effect around an airplane's shadow as viewed from the airplane.

    Fred
     
    Fred McKenzie, Apr 25, 2007
    #32
  13. FlintStone

    Alan Browne Guest

    See my other reply. I recanted.
     
    Alan Browne, Apr 26, 2007
    #33
  14. FlintStone

    Tony Polson Guest


    Isn't 2 days old actually 1/7th?

    14 days of waxing + 14 days of waning = 28 day cycle.

    2 days out of 14 is 1/7th.
     
    Tony Polson, Apr 26, 2007
    #34
  15. FlintStone

    M-M Guest


    The waning moon is from 14-28 days old.
     
    M-M, Apr 26, 2007
    #35
  16. FlintStone

    Tony Polson Guest


    That's what I said. 14 days to wax, 14 days to wane.

    Therefore 2 days into waxing is 2/14ths, or 1/7th.
     
    Tony Polson, Apr 26, 2007
    #36
  17. FlintStone

    M-M Guest


    By your logic, a 7-day moon would be 1/2.

    And a 21-day moon? 1-1/2??

    I'm done with this silly argument
     
    M-M, Apr 26, 2007
    #37
  18. FlintStone

    Tony Polson Guest

    Yes, after seven days it is half moon.

    00 days - new moon (moon dark)
    07 days - half moon (left half of disc illuminated)
    14 days - full moon (fully illuminated)
    21 days - half moon (right half of disc illuminated)
    28 days - new moon again - cycle repeats every 28 days
    No, don't be silly! It is half moon (see above).
    Thank goodness for that!

    It is easy to get confused where the terms "first quarter" and "third
    quarter" are sometimes used to describe 7 and 21 days into the 28 day
    cycle. Those terms may correctly describe the fraction of the cycle
    that has been completed, but they are misleading in practice because
    the moon is half illuminated, hence "half moon".

    Try these web sites for a more detailed explanation:

    http://www.enchantedlearning.com/subjects/astronomy/moon/Phases.shtml
    (scroll down to "HALF MOON" in the centre of the page)

    http://www.astro.wisc.edu/~dolan/java/MoonPhase.html
    (in the drop down box marked "Point of view", select "Earth view")
     
    Tony Polson, Apr 26, 2007
    #38
  19. FlintStone

    M-M Guest

    I thought I was done.

    A 7-day moon is called a first quarter to everyone else on earth. You
    can call it whatever you like.
     
    M-M, Apr 26, 2007
    #39
  20. Yes, the shadow of the grains is a "retro-reflection" effect,
    as is the constructive interference of light I also discussed.
    In retro-reflectors, the design is specifically made to reflect
    light back using a specific geometry. In natural surfaces, it is
    random orientations that do it.
    Yes, I've seen this multiple times from aircraft, most commonly
    near takeoff and landings when the ground isn't too far away.
    You can see it with vegetation too. I've seen it over trees,
    and grasses as well as soils. An opposition surge can be quite
    strong with dew on plants. I photographed some nice ones
    in Tanzania on the Serengeti this January.

    Roger
     
    Roger N. Clark (change username to rnclark), Apr 29, 2007
    #40
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