Sony Alpha 100 DSLR snapshot at night - Venus and Moon

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

  1. FlintStone

    FlintStone Guest

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


    In case you want to see the results of 2 seconds at f6.3, ISO 200, pointed up at
    the night sky.

    I used the Sony 18-200 3.5-6.3 lens, (@135mm) and a very good tripod...

    Venus and the Moon are quite close these days...
     
    FlintStone, Apr 21, 2007
    #1
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  2. FlintStone

    RichA Guest

    Venus is brighter than the Moon (surface area) so I would expose for
    the Moon itself, something around
    1/125th of a second at f8 or so, depending on the phase. With the
    lens at 200mm, you should be able to spot meter the Moon. If you can,
    expose about 1 stop over indicated. That way you'll avoid massively
    burning out the images.
     
    RichA, Apr 22, 2007
    #2
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  3. FlintStone

    Alan Browne Guest

    If there was any need of proof that you know nothing at all about
    photography, the above is probably it.

    The moon should be shot "fastest" at about sunny 16. For ISO 100 that
    would be f/16 1/100. 2/3 to 1 stop less light will work well in most
    cases.

    1/125 at f/8 is a stop too much light.
     
    Alan Browne, Apr 22, 2007
    #3
  4. FlintStone

    Alan Browne Guest

    The moon is completely burned out. No detail at all.

    The moon needs a sunny-16 exposure for the moon. eg: for ISO 200 about
    f/22 1/100. Another stop less would not hurt.

    Cheers,
    Alan
     
    Alan Browne, Apr 22, 2007
    #4
  5. FlintStone

    FlintStone Guest


    Hi Alan. yes I know that, I put up that picture to show the dark circle of the
    moon exposed, and a few stars, and the fact that there is no noise apparent in
    the black.

    I took a bunch of pics, I'll see if there is one closer to normal exposure!

    (I was quite rushed during that time...)
     
    FlintStone, Apr 23, 2007
    #5
  6. FlintStone

    RichA Guest

    It depends on the PHASE of the Moon, clueless.
    The surface brightness varies with phase.
    Besides, I was ballparking since you should always bracket a subject
    like that.
    http://www.shaystephens.com/moon_calc.php

    Stop acting like a little B----- because I criticized your precious
    Pentax 2000 years ago.
     
    RichA, Apr 23, 2007
    #6
  7. FlintStone

    Alan Browne Guest

    You're the one suggesting that someone expose MORE than indicated to
    "avoid massively burning out the image". That's clueless.
    No it does not. The lit part is always the same brightness, there is
    simply less of it (surface) in the view finder.

    The only thing less is the amount of moonlight reaching the earth so a
    moonlit scene on earth would need more exposure.

    The amount of sunlight reaching the moon does not change with phase, and
    that is what is what needs to be exposed even if but the slimmest
    sliver. The point is to record detail not a blob of light.
    The hoary old adage of Sunny-16 is the starting point, bracketing or
    not. Your advice was 1.7 stops over from that starting point.
    As it has been clearly shown that you're not a photographer, what you
    criticize is about as relevant as ... you. Not at all relevant.
     
    Alan Browne, Apr 23, 2007
    #7
  8. FlintStone

    RichA Guest

    You overexposure by a certain amount because the moon is NOT a 16%
    greycard. You want it to look white while still retaining detail.
    Additionally, shots of the Moon underexposed sometimes show noise
    which can be avoided with a correct exposure.

    Here's one of my Moon shots, let see yours:

    http://www.pbase.com/andersonrm/image/65063908
     
    RichA, Apr 23, 2007
    #8
  9. FlintStone

    Alan Browne Guest

    That's not what you said. YOU said to expose more to avoid burning.
    You did not refer to metering (which is also a dead wrong way to shoot
    the moon in the first place.
    I don't shoot the moon. I have in the past with a 75-300 lens and the
    result, while well exposed, is simply not sharp. Other than that I'm
    totally disinterested in the subject.

    Telling people "to expose more" to "avoid burning out" is simply wrong.
    Admit that.
     
    Alan Browne, Apr 23, 2007
    #9
  10. FlintStone

    RichA Guest

    Then why bother chiming in at all?
     
    RichA, Apr 23, 2007
    #10
  11. FlintStone

    Alan Browne Guest

    To warn people about your very bad advice.
     
    Alan Browne, Apr 23, 2007
    #11
  12. FlintStone

    RichA Guest

    I admit it, I worded it wrong.
     
    RichA, Apr 23, 2007
    #12
  13. (Alan, I bet you know most of this; I'm just trying to write
    up a general explanation for everyone.)

    The surface brightness of the moon does vary with phase. The
    areas close to the terminator are darker, thus lower in surface
    brightness. This is a cosine of the solar altitude effect.
    As the sun gets closer to the horizon, the photons per square
    meter per second decreases on the moon just like on the
    earth (and all other planets too). The crescent moon, e.g.
    the one in the image in this thread has most sunlight incident at
    a low angle, so the surface brightness is low, and decreasing
    closer to the terminator.

    As we get closer to full moon, the sun will be illuminating the sun from
    behind us as we look at the moon. In this case the cosine incidence
    effect is compensated by our view as we look toward the
    terminator (which is at the edge of the lunar disk) so we see more area
    per pixel (or square angular area) near the edge of the moon.
    The increase in surface area per pixel cancels the decrease in
    photons per square meter so the moon's surface brightness does
    not change over the disk as it does at other phases.

    Then at very close to full moon, the micro shadows cast by grains
    in the lunar soil decrease from this perspective causing the
    full moon to appear even brighter.
    The is called the opposition surge (not to be confused with the
    other "surge" going on right now) or opposition effect.
    This effect can also be seen with soils on Earth when you see a halo
    around the shadow cast by your head. Another factor contributing to
    the opposition effect is constructive interference of light making the
    brightness even higher (this was controversial a decade or so ago but has
    now been proven so all the research scientists in this area pretty much
    agree).

    The moon has a reflectance lower than the average reflectance of the Earth,
    so the average exposure is more like sunny f/11 rule, but when there is low solar
    incidence angle, exposures become longer (when the moon is a crescent),
    and shorter near full moon when the opposition surge is significant.

    Then guess when happens when the moon is within about 2 degrees of
    full moon? Is it bright due to the opposition surge?
    No, it becomes very dark!
    It's an eclipse! ;-)

    Roger
     
    Roger N. Clark (change username to rnclark), Apr 24, 2007
    #13
  14. FlintStone

    Alan Browne Guest

    I accept that, but I don't agree that the above results in more than 2/3
    stop of difference in exposure for 1/2 or 1/4 moon shot. Rich's post
    went 2 stops beyond the common "rule".

    Never mind suggesting an "increase in exposure" to "avoid burnout". He
    now "retracts" that, of course.
     
    Alan Browne, Apr 24, 2007
    #14
  15. FlintStone

    RichA Guest

    Does that date back to when people didn't even have built-in camera
    meters let alone spot metering?
     
    RichA, Apr 24, 2007
    #15
  16. FlintStone

    Alan Browne Guest

    Yep. http://www.pbase.com/shootin/image/71244103
    (Actually opend up 2/3 stop as the sun was setting, but didn't use a
    meter). Slide film.
     
    Alan Browne, Apr 24, 2007
    #16
  17. FlintStone

    RichA Guest

    The Moon (right now) is a crescent. In a few days it will be full.
    People can experiment.

    Because that part was a mistatement.
     
    RichA, Apr 24, 2007
    #17
  18. FlintStone

    FlintStone Guest

    FlintStone, Apr 24, 2007
    #18
  19. FlintStone

    M-M Guest


    The above statement is incorrect.

    First, at a "slim sliver" you are only seeing the terminator portion
    which is really twilight. At a larger phase, the round side is much
    brighter. When full, the entire moon is lit like high noon.

    Also, exposure not only depends on the phase but how high in the sky the
    moon is. When low, you are looking through a lot more atmosphere.

    Getting back to the original post, I believe the exposure was correct.
    Mr. Flintstone wanted to capture the "old moon in the new moon's arms"
    and overexposing the sliver was the only way to do that.

    Here is a moon photo I just took tonight:

    <http://www.mhmyers.com/d80/DSCN3780w.jpg>

    And here is a page I made about photographing the moon:

    <http://www.mhmyers.com/moon.tn.html>
     
    M-M, Apr 24, 2007
    #19
  20. For some obsure reason you are targeting Rich and losing the fight Alan.
    Why not apply your own criticism of him to yourself? I have yet to see a
    photo of yours to equal many of Rich's. If he claimed you were a shitty
    photographer would be more poignant. But then he has more taste than to sink
    to your level.

    FWIW his moon shot is one of the few I've seen that I would consider
    exemplary yet you don't even have the grace to acknowledge it as good or
    even fair photo. Why is that?

    First off you abuse him about not being a photographer and when he post
    evidence his is, you change tack and try to continue your lame attack on
    him. If you contributed 10% of what Rich does to this group you'd have some
    credibility but just because you participated in it's origin does not give
    you any right whatsoever to critisize those who make it what it is today.
    Get a life and lay off the flame baits.
     
    Anonymous # 998792, Apr 24, 2007
    #20
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