Battery Junction - Olight
Results 1 to 17 of 17

Thread: do i neeed to change apature?

  1. #1

    Default do i neeed to change apature?

    aint it smart to just lkeave it at widest setting?

  2. #2
    Flashaholic*
    Join Date
    Apr 2001
    Location
    Massachusetts
    Posts
    4,857

    Default Re: do i neeed to change apature?

    Generally you'll get sharper pics if you step it down a bit but then of course you'll need a slower shutter speed so am more susceptible to hand shake.

  3. #3
    Flashaholic* Xrunner's Avatar
    Join Date
    Aug 2002
    Location
    Colorado
    Posts
    1,594

    Default Re: do i neeed to change apature?

    raggie, are you using a digital or film camera? I've found that for digitals it's usually pretty good if you just leave them on the auto setting most of the time.

    -Mike

  4. #4
    Flashaholic*
    Join Date
    Apr 2002
    Location
    Boise, ID
    Posts
    2,639

    Default Re: do i neeed to change apature?

    To expand on what geepondy said...

    The aperture (F-stop) controls how much light gets to the film/sensor in a camera. The higher the number, the less light gets in, and the longer the exposure.

    Changing your aperture by a "full stop" means changing it so your exposure doubles or is cut in half.

    For instance:

    If you shoot a picture, and your camera says: 1/60, F2.0

    Changing the aperature to these value will cause the exposure to be affected as such:

    <font class="small">Code:</font><hr /><pre>
    F-stop Exposure (seconds)
    2.8 1/30
    4.0 1/15
    5.6 1/8
    8.0 1/4
    </pre><hr />

    So F/8.0 lets in 16 times less light, so using that setting, the exposure must be 15 times longer. If you change your camera from F/4.0 to F/5.6, your exposure will be twice as long.

    If you need a specific shutter speed, you can adjust the aperture to get the proper exposure.



    The other thing that aperture affects is depth of field - which is how much is "in focus". The higher the F-stop number, the larger the depth of field, so more will be in focus.

    So, let's say you take a picture of something, using F/2.0, and the depth of field ends up being 1 foot. That means that everything from 6" in front to 6" behind whatever you focused on will be considered "in focus" (it's not really split 50/50 like that, but we'll skip that for simplicity).

    So increase the F number to 8.0. Now your depth of field may be 5 feet (depends on the lens and lots of other factors). So everything from 2.5 feet in front of, to 2.5 feet behind what you focused on will be considered "in focus".

    Finally, there is usually a "sweet spot" for sharpness, that's generally around halfway between the ranges of F-stops the lens will do. On my camera, the range is F/2.0 - F/8.0. The sweet spot is at F/5.6. Things are a touch more blurry and you get some color artifacts at F/2.0, and a touch blurry at F/8.0. At F/5.6, my camera lens is providing optimal image sharpness.


    If you're trying to achieve some specific effects with your picture, you can use aperture to do that. If you want a lot of the picture in focus, use a high F-number (like F/8.0). If you want just your subject in focus, but the background blurred, use a low F-number (like F/2.0).

  5. #5
    Flashaholic danielo_d's Avatar
    Join Date
    Jul 2003
    Location
    NorCal
    Posts
    359

    Default Re: do i neeed to change apature?

    Hey, Ragz, check this out.
    Kinda cool simulation.
    For the aperature part, go to here.

    It's called the simcam. Gives you and idea of what to expect under various conditions.

    Or just play with your camera. Tak alot of shots. Write down the settings for each shot. Then view them on your PC's monitor and see how each change affects the picture. Sounds tedious, but think how it was/is for doing the same with film SLR's. U don't have to wait for developing [if you don't have your own lab.]
    Enjoy! [Another expensive hobby, eh Ragz?!?!?]

    btw, glad 2c you're feeling better.

    Danno

  6. #6

    Default Re: do i neeed to change apature?

    Hello Raggie,
    The first photo was shot at f-stop 4, shutter speed 1/125.


    The next one was shot at f-stop 22, shutter speed 1/4.


    Focus was adjusted to the very front of the bezel for both images.
    You will see how the `depth of field` gets deeper (more area in focus).
    Last edited by nekomane; 09-06-2009 at 12:21 PM. Reason: Updated link to pics

  7. #7

    Default Re: do i neeed to change apature?

    man there is so much to learn.i wanna learn to take pics of moon when it gets full

  8. #8
    Moderator
    arewethereyetdad's Avatar
    Join Date
    Nov 2003
    Location
    Kansas City, MO
    Posts
    7,708

    Default Re: do i neeed to change apature?

    nekomane, that was a REALLY good description, with the photos. Thanks for the education.

  9. #9
    Flashaholic* MaxaBaker's Avatar
    Join Date
    Dec 2004
    Location
    South Jersey
    Posts
    2,260

    Default Re: do i neeed to change apature?

    Hey raggie,

    with that 12x optical zoom, how far can you soom in on the moon? Is it far enough to see craters and stuff?

    I'm not really interested in digital zoom [img]/ubbthreads/images/graemlins/sick2.gif[/img]

  10. #10

    Default Re: do i neeed to change apature?

    i kinda doubt it baker i can try tomorow.i wish i had a teloscope that can hook to it

  11. #11
    Flashaholic*
    Join Date
    Aug 2004
    Location
    Dallas, TX
    Posts
    616

    Default Re: do i neeed to change apature?

    [ QUOTE ]
    raggie33 said:
    i kinda doubt it baker i can try tomorow.i wish i had a teloscope that can hook to it

    [/ QUOTE ]

    Here's my weak attempt at photographing the moon through my telescope:



    I'm not a wizard at this by any means. This was taken with my digital camera, afocally mounted on a little Meade ETX 105mm telescope. I used a 26mm eyepiece in front of the camera lens. This was my first attempt, and pretty much beginners luck - it's hard to focus.

    Best of luck on your attempt raggie! A tripod helps a lot. I'd think you could get at least some detail at 12x.

  12. #12

    Default Re: do i neeed to change apature?

    cool picit came vout great does the moon ever get closer to earth.i see on tv sometimes where it looks huge

  13. #13
    Flashaholic
    Join Date
    Oct 2004
    Location
    Bay Area
    Posts
    180

    Default Re: do i neeed to change apature?

    BTW Rags, you might want to get a tripod for your cam if you don't have one yet. It takes away a lot of 'shake' when taking pics in low light conditions/night shots.

  14. #14

    Default Re: do i neeed to change apature?

    ok im still confused i read many websites and still confussed..ok a smaller number lets in more light?now whcih one has the bigest area that will be in focus.man this is confuseing as hecti like this hobby but man there is much to learn. i still have my old pentax k1000 to

  15. #15

    Default Re: do i neeed to change apature?

    o i readred it and i think i got it by looking at pic. is there a rule is it better to alwyas use slower shuter speed and biger apature number?like f22

  16. #16
    *Flashaholic* Flying Turtle's Avatar
    Join Date
    Jan 2003
    Location
    Apex, NC
    Posts
    6,388

    Default Re: do i neeed to change apature?

    I suppose you could say to use the slowest shutter speed you can without blurring your pic in order to get the greatest depth of focus. This won't work if you are trying to stop motion, but it might be a good rule of thumb.

    Geoff

  17. #17
    Flashaholic*
    Join Date
    Aug 2004
    Location
    Dallas, TX
    Posts
    616

    Default Re: do i neeed to change apature?

    [ QUOTE ]
    raggie33 said:
    cool picit came vout great does the moon ever get closer to earth.i see on tv sometimes where it looks huge

    [/ QUOTE ]

    Thanks! Yeah, the moon does get closer to the earth by a little bit - but it's not terribly easy to notice the difference. The main thing that makes the moon look larger is how close it is to the horizon or the zenith. When the moon is low in the sky, it looks huge, and when it's high overhead it tends to look smaller. It is, in fact, the same size - it just looks bigger when it's low. This is an optical illusion.

    Also, they can cheat on TV... [img]/ubbthreads/images/graemlins/tongue.gif[/img]

Posting Permissions

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