A&P Rebel XT owners. Question about aperture.

Discussion in 'Lifestyle' started by forgotmyname, Nov 13, 2007.

  1. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    I just got the camera like a few days ago and I am still trying to learn how to use it. Anyways, I am trying the aperture tutorial, and the lenses are responsive at a high aperture, but really slow the more I increase the number/decrease the aperture. Is this normal?

    When is high aperture useful?
     
  2. onedownfiveup

    onedownfiveup Active Member

    Joined:
    Jun 26, 2005
    Messages:
    18,222
    Likes Received:
    0
    Location:
    KC
    I suggest reading your camera's manual. It will help you.
     
  3. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    What do you think I am doing? :ugh:
    That's why I said, I am reading the tutorial and trying the camera at the same time.
     
  4. aCab

    aCab New Member

    Joined:
    Jun 1, 2007
    Messages:
    18,292
    Likes Received:
    0
    Location:
    Chicaaago
    There is a relationship between shutter speed, aperture, and ISO. Once you figure it out, you'll be good to go. Took me a few weeks, but I got it. Read up more.
     
  5. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    Ok, I'll keep on reading.
     
  6. aCab

    aCab New Member

    Joined:
    Jun 1, 2007
    Messages:
    18,292
    Likes Received:
    0
    Location:
    Chicaaago
    Ok, there's not much going on here so I thought I'd type a little bit of info for you.

    The camera is sensitive to light. Think of the aperture as a ring with will expand and contract. At a high number, such as f/22, the hole is very small (larger numbers equal smaller openings). As such, you need to let the shutter stay open longer to let more light in. Conversely, a wide aperture such as f/1.8 would let a lot of light in, therefore necessitating a faster shutter speed.

    So, larger number (smaller physical) aperture = needing to use a slower shutter speed and a smaller number (larger physical) aperture needs a faster shutter speed.

    Try putting your camera on manual (the "M" mode) and mess around. You'll start to understand what I mean.

    Then you can figure out ISO settings next. Have fun!
     
  7. Tedrzz

    Tedrzz New Member

    Joined:
    Jul 6, 2005
    Messages:
    1,578
    Likes Received:
    0
    Location:
    Brooklyn, NY
    Photography is a world of opposites. HIGH f-stops means LOW shutter speeds, under exposure on a film negative means under exposure on a print...etc..

    Heres the low down:

    Use a small (aka f/8, f/11, f16, f/22) when you are taking general landscape shots, OR really close shots of a flower or something.

    Try this: Put your thumb a few inches from your nose and focus on it. Notice how the background is really blurry? Now move your thumb an arms length away. Notice how the background is more in focus? If you use a really large aperature (f/1.4, f/2, f/2.8) when you are really close to a subject then only a tiny fraction of the object is going to be in focus.

    Notice how I'm saying small f-stop = f/8, f/11, f/16? That is refering to the physical size of the aperature blades in your lens when you stop it down. The hole get's smaller.

    Large f/stops such as f/1.4, f/2, f/2.8 are called large just because the opening on the lens is larger.

    So with that being said, large f-stops are good for portraits because it isolates the subject, and more importantly- what you want the viewer to look at. Large fstops are also really good for low light photography because with a larger f/stop you can get a higher shutter speed.

    So lets think about that.

    Small f/stop = slow shutter speed (so only use it in the daylight when you can still have a fast shutter speed so your pictures aren't blurry.)

    Large f/stop = fast shutter speed.

    Why use a smaller f/stop? Because alot of lenses wide open (large aperture) don't have as good of image quality if they are stopped down (small f/stop).

    Even my 1,600 dollar 70-200 f/2.8 doesn't have as great of image quality at f/2.8 as it does at f/5.6.


    Keep reading your manual, and most importantly just keep shooting. The best thing about digital is that you can see instant results of what setting does what. Good luck and have fun.

    Ted
     
  8. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    Thanks.
     
  9. iridium130

    iridium130 OT Supporter

    Joined:
    Jan 7, 2005
    Messages:
    6,034
    Likes Received:
    0
    Location:
    Anaheim Hills, CA --> Denver, CO
  10. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    Ok I am reading about the f/stops and it is too fucking confusing. All I know is that the f/stop is a ratio between the size of the lense and the focal length but why do I need to know the area of the aperture is beyond me.
     
  11. dano

    dano OT Supporter

    Joined:
    Aug 28, 2006
    Messages:
    42,307
    Likes Received:
    0
    Location:
    Far enough outside Detroit
    You can learn by just playing with the camera. Use Tv (time value, your shutter speed) or Av (aperture value, aperture obviously). Walk around and shoot random crap around your house in different modes with different values.

    Go outside and point the camera at a street light from a distance in Av at the lowest aperture (likely f/5.0 if you're using the kit lens). It will use a long shutter speed. Come back inside and shoot a lamp with the same aperture and watch how much faster the shutter speed is.

    Same goes for the shutter speed. Take a shot of that street light in Tv at 1/200 and it'll be so dark you can't see it, but try it at 5 seconds and watch how much brighter the picture is. Also watch what aperature it chooses, it will be very low. Come back inside, shoot that lamp, and it will choose a quicker shutter speed.

    Hope that makes some sense. The other guys are doing a great job explaining it, but the Tv/Av modes on your camera are awesome at teaching you what situations are appropriate for specific settings.
     
  12. aCab

    aCab New Member

    Joined:
    Jun 1, 2007
    Messages:
    18,292
    Likes Received:
    0
    Location:
    Chicaaago
    This is your first problem.
     
  13. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    You mean the actual spelling which I already fixed?
     
  14. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    I'd do that but it is too fucking chilly outside. Besides, this is not a one night thing. I am going to keep on doing this along the days.
     
  15. aCab

    aCab New Member

    Joined:
    Jun 1, 2007
    Messages:
    18,292
    Likes Received:
    0
    Location:
    Chicaaago
    No, i mean the info there is totally wrong.
     
  16. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    Nevermind. I got it. I just gotta keep reading this multiple times in order to get it.
     
  17. Derrict

    Derrict No, I am not Amish OT Supporter

    Joined:
    Nov 19, 2003
    Messages:
    9,484
    Likes Received:
    1
    Location:
    Amish Country, PA
    Don't expect to learn it all in one day. Most people take a few days, weeks, or months to absorb the info. If you're good at math and ratios, it's pretty straight forward once you learn the basics. The way I try to explain to newbies is like a balance scale. You take away from one side and you need to balance the other side to get the proper exposure.

    In photoraphy terms, let's say you expose an image and the settings are ISO 100, f/4.0, 1/60. Now you want more depth of field so you change the aperture to f/5.6. To expose the same image properly, you either increase the ISO one stop or you use a slower shutter speed, or a combination of both. To keep it simple, you would either use:
    ISO 200, f/5.6, 1/60
    or
    ISO 100, f/5.6, 1/30

    It's a system of checks and balances. The settings you choose are dependant upon numerous variables. There will be certain limits based upon how high of ISO you're willing to go (more noise) and/or how slow of a shutter speed you can hand hold, among other things.
     
  18. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    One more thing, which I am going to read more tomorrow. The depth of field. Does this mean, the more stuff I get to picture like taking a picture of a candle to a group of people?
     
  19. KungFool7

    KungFool7 keep driving—it's getting earlier

    Joined:
    Jun 22, 2005
    Messages:
    1,122
    Likes Received:
    0
    DOF is the range of focus.

    the more closed the aperture (higher the aperture number), the deeper the DOF.

    If you take a shot of your dick, looking straight on, and just want the head to be in focus, use something like F/2 or F/5.6, depending on the length of your manhood.

    If you want to be able to count the hairs on your balls as well as the creases on your dickhead, use a higher aperture like F/11 or F/22, once again depending on the length of your manhood.
     
    Last edited: Nov 13, 2007
  20. tetsuo

    tetsuo And shepherds we shall be...

    Joined:
    May 6, 2004
    Messages:
    9,444
    Likes Received:
    0
    :bowrofl: that is one hell of a way to explain it
     
  21. frostedfrank

    frostedfrank OT Supporter

    Joined:
    Oct 2, 2003
    Messages:
    6,754
    Likes Received:
    4
    Location:
    Ottawa, Canada
    :rofl::rofl:
     
  22. GregFarz78

    GregFarz78 New Member

    Joined:
    Oct 28, 2002
    Messages:
    64,128
    Likes Received:
    0
    Location:
    Philly, PA
    download this and read a few times

    http://arcticfurrer.com/otap/dcam_m... Understanding Exposure (Revised Edition).pdf
     
  23. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    Ok, some people need to set a standard aperture measurement. Some say f/22 is a higher aperture when it is in fact, the lowest one. Even the Canon manual says it. At f/22, the lenses are opening at its smallest size, thus you can only take a picture of something close.

    At a higher aperture like f/3.5 which is my 55mm kit lenses, I can take a picture of a bigger picture.
     
  24. GregFarz78

    GregFarz78 New Member

    Joined:
    Oct 28, 2002
    Messages:
    64,128
    Likes Received:
    0
    Location:
    Philly, PA
    take a picture of a bigger picture?
     
  25. forgotmyname

    forgotmyname Active Member

    Joined:
    Jul 18, 2007
    Messages:
    13,959
    Likes Received:
    0
    :eek3:
    Well you are essentially taking a picture of the bigger picture.
     

Share This Page