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  1. #81
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    ok, that kind of clarified things a little more. I didnt know i had to be a math genius though lol

  2. #82
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    Quote Originally Posted by Switchblade906 View Post
    ok, that kind of clarified things a little more. I didnt know i had to be a math genius though lol
    You dont it becomes second nature. I never do all that math when I shoot. Your histogram is your friend. Keep looking at that after each shot till you get the right exposure. Keep shooting!!!

    Frank
    Sony A77
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    Maxxum 400si.
    Sony 18-70 Kit Lens
    Minolta AF 35-70
    Minolta AF 50 f/1.7
    Tamron 70-300 f/4-5.6 Di LD
    Tamron 60mm Macro
    Tamron 17-50 f/2.8
    Tamron 2x Converter
    Sony HVL-F42AM
    Quantaray 70-300 4.5-5.6 Macro
    Slingshot 200 Bag



    http://www.flickr.com/photos/22083244@N06/

    http://s305.photobucket.com/albums/nn219/sparkie1263/

  3. #83
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    Quote Originally Posted by sparkie1263 View Post
    You dont it becomes second nature. I never do all that math when I shoot. Your histogram is your friend. Keep looking at that after each shot till you get the right exposure. Keep shooting!!!

    Frank
    i was looking through my menu last night and found out where that was and turned it on. its not like some of the other cameras i was looking at. its not in color and its also very small. oh and i turned on that rule of thirds line graph thing on the screen too

  4. #84
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    I didn't know that you could turn the histogram on and off on the A33.

    As Frank says it certainly helps to avoid (or correct) this.

    Name:  Switch.jpg
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  5. #85
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    what am i trying to avoid or correct?

  6. #86
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    Underexposure.
    Just looking at the image you can see it's dull and flat.
    A Histogram is a graphical representation of the pixel count with dark pixels at the left and light pixels on the right.
    This Histogram is lacking any pixels in the right hand part of the graph indicating underexposure.
    Underexposure limits dynamic range, loses colour information and increases digital noise.

    Compare it to this one...

    Name:  Histogram.jpg
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  7. #87
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    ok so tell me if this one is better


  8. #88
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    Dec 2007
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    1,760
    Is there going to be a test?


    Quote Originally Posted by Peekayoh View Post
    Well, it sounds complicated but it's really quite simple.
    You just need to get a few simple rules fixed in your head.

    1) [i]ISO.[/i]
    The best IQ is achieved at low ISO. Less noise and better Dynamic Range.
    To put that in perspective at
    ISO 100 S/N ratio = 38.8dB, Dynamic Range = 12.57EV
    ISO 800 S/N ratio = 29.9dB, Dynamic Range = 10.03EV

    To apply ISO numbers, which are actually film speeds, to a digital sensor is a bad thing IMO.
    The correct term is "gain" because what happens when you step up the ISO number is that, just like a volume control, the camera amplifies the signal.
    The problem is that amplifying the signal, amplifies the digital noise as well, so then you need to apply noise reduction techniques which leads to all sorts of problems, notably loss of detail.

    Conclusion, use the lowest ISO possible in any given situation.

    2) [i]SHUTTER SPEED[/i]
    Below 1/60 second. Good for static subjects, Landscapes, still life.
    Below 1/125 second. Good for portraits, sleeping babies....
    1/125 second. A useful everyday setting and ok for a person walking normally.
    1/250 second. Freeze a person jogging slowly.
    1/500 second. Freeze people running, bycicles, cars etc.
    1/1000 second. Freeze racing cars, planes etc.

    Conclusion, the choice is yours.

    3) [i]APERTURE[/i]
    Smaller apertures (bigger numbers) are good for maximising DOF, so f/8 to f/16 is good for Landscapes. The downside is that the shutter speed will be lower and you may need a support.
    Larger apertures (smaller numbers) are good for blurring the background and good for shortening the shutter speed to avoid camera shake and motion blur.

    4) [i]RELATIONSHIPS[/i]
    Fortunately, or rather deliberately, the relationships between the preceding three parameters are linear.
    That is to say that if you double one of the values you need to halve one of the other two values to keep the exposure correct.
    If you halve one value, you need double one of the other two.
    A combination does the job too.

    We would normally say decrease or increase by "One Stop" which means the same as halving or doubling the light admitted to the camera.

    To put all this in the context of the shot of your Niece.
    You took it at ISO1600 - f/4.5 - 1/40th sec.
    At that shutter speed you know the shot will suffer from motion blur and you're already at max aperture so the only thing you can do is +2 ISO and -2 on the shutter.
    i.e. ISO6400 - f/4.5 - 1/160th
    The result will probably be highly unsatisfactory because, if you're shooting JPEGS, the motion blur will be gone but the in camera noise reduction will rob the image of a lot of detail.

    Which is where the "fast" 35mm f/1.8 lens comes into it's own and you have more options.
    Moving from f/4.5 up to f/1.8 gives you +2.66 stops to play with.
    So shifting both the shutter and ISO by -1.33 stops gives you ISO 640 and 1/100th sec.

    That all sounds horrendously complicated but in reality it's simplicity itself.
    You know you're in a low light situation so you know you need close to maximum aperture and you know that 1/100 sec is needed to avoid motion blur.
    So select iso400 and set the aperture wide open in (A)perture mode.
    Meter the subject and see what shutter speed the camera has chosen if it's around 1/100th or more you're good to go.
    If not, bump up the ISO until it is.

    The 1/3 stops complicate things but here's a useful chart.

    Attachment 55440

  9. #89
    Join Date
    Dec 2007
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    1,760
    you tube can teach you a lot too..

    http://www.youtube.com/watch?v=Q3yiz1sBKLc

  10. #90
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    Nov 2008
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    Quote Originally Posted by SONYNUT View Post
    Is there going to be a test?
    Yes, and pocket calculators are banned.
    Failing to meet the required grade will result in confiscation of equipment, my discretion.
    Guess who's going to fail?

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