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Thread: Lens name

  1. #1

    Default Lens name

    Hi i've been reading from the net and some treads in this forum but i still cant understand whats the len's aperture purpose? what does it do?

    Take for example the 50mm f1.8, i understand that aperture 1.8 means the hole is big. I read about it affecting the shutter speed and the dof too.

    Any one can explain to me? Really very confuse over this.

  2. #2
    Member eosandy's Avatar
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    Default Re: Lens name

    Really, just type "wiki:aperture" in google.
    Learning DSLR control http://stormtrigger.blogspot.com/

  3. #3

    Default Re: Lens name

    Yes i read there b4 but i still cant realli understand. is there any simple way to understand and get it stuck to my brain

  4. #4

    Default Re: Lens name

    reading up and understanding will get stuck in your brain longer.

    google up on aperture, shutter speed, depth of field
    u shld be clear after that

  5. #5

    Default Re: Lens name

    Read you manual, it explains it too. Read the newbies guide, it explains it too. Research on google, it explains it too.

    If after all that you still can't understand, then maybe you're not ready to venture beyond "auto" in your DSLR.
    Alpha

  6. #6
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    Default Re: Lens name

    Quote Originally Posted by xtin88 View Post
    Hi i've been reading from the net and some treads in this forum but i still cant understand whats the len's aperture purpose? what does it do?

    Take for example the 50mm f1.8, i understand that aperture 1.8 means the hole is big. I read about it affecting the shutter speed and the dof too.

    Any one can explain to me? Really very confuse over this.
    Hole bigger means collect more/less light? If there is more light should the shutter be faster or slower? Alternatively, what if there is less light?

    If you can figure this out, just try memorizing until it becomes second nature....

  7. #7

    Default Re: Lens name

    Quote Originally Posted by kaixiang View Post
    Hole bigger means collect more/less light? If there is more light should the shutter be faster or slower? Alternatively, what if there is less light?

    If you can figure this out, just try memorizing until it becomes second nature....
    If hole bigger, it will collect more light. and if there is more light, shutter speed will be faster. and if there is less light, means hole smaller and iso have to be high and that will make the shutter speed slow?

    I don't know if i'm making any sense.

  8. #8

    Default Re: Lens name

    Quote Originally Posted by xtin88 View Post
    If hole bigger, it will collect more light. and if there is more light, shutter speed will be faster. and if there is less light, means hole smaller and iso have to be high and that will make the shutter speed slow?

    I don't know if i'm making any sense.
    Photography is about light (exposure). To get a good photo, you need a certain amount of light, say X. For X amount of light to reach the sensor, is dependant on the aperture and the shutter speed (ignore the ISO first)

    If aperture smaller (f no bigger) you need longer time (longer shutter speed=f/smaller number) to achieve X amt of light.

    But if the sensor is more sensitive (higher ISO), this X amt of light can be achieve faster given the same aperture/shutter speed setting

    It is all physics
    Idea got, execution not!
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  9. #9
    Senior Member limwhow's Avatar
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    Default Re: Lens name

    Quote Originally Posted by xtin88 View Post
    If hole bigger, it will collect more light. and if there is more light, shutter speed will be faster. and if there is less light, means hole smaller and iso have to be high and that will make the shutter speed slow?

    I don't know if i'm making any sense.
    Yes, yes, xtin88. So far so good.

  10. #10

    Default Re: Lens name

    Quote Originally Posted by two200 View Post
    Photography is about light (exposure). To get a good photo, you need a certain amount of light, say X. For X amount of light to reach the sensor, is dependant on the aperture and the shutter speed (ignore the ISO first)

    If aperture smaller (f no bigger) you need longer time (longer shutter speed=f/smaller number) to achieve X amt of light.

    But if the sensor is more sensitive (higher ISO), this X amt of light can be achieve faster given the same aperture/shutter speed setting

    It is all physics
    Okok i think i got it!! but just get confuse with so many things goin through my mind right now.

    So if its small f/no, shutterspeed fast cos got alot of light for the picture already. Whereas if is big f/no, shutterspeed slow as it need to take a longer time to collect light into the lens. Am i getting it?

  11. #11

    Default Re: Lens name

    Quote Originally Posted by xtin88 View Post
    Okok i think i got it!! but just get confuse with so many things goin through my mind right now.

    So if its small f/no, shutterspeed fast cos got alot of light for the picture already. Whereas if is big f/no, shutterspeed slow as it need to take a longer time to collect light into the lens. Am i getting it?

    That is correct!
    Idea got, execution not!
    APAD|Travelogue

  12. #12

    Default Re: Lens name

    Great! ok i got a last qn. if a lens indicate e.g 50mm f1.8. It means the hole is big and it is in its maximum opening size already right? what if my camera i set my aperture to over 1.8?

  13. #13

    Default Re: Lens name

    Quote Originally Posted by xtin88 View Post
    Great! ok i got a last qn. if a lens indicate e.g 50mm f1.8. It means the hole is big and it is in its maximum opening size already right? what if my camera i set my aperture to over 1.8?
    what do you mean by over 1.8? the lens can't physically open up its aperture any further past f/1.8, so it stops at f/1.8 if you turn the dial in your cam..

    if you mean a larger no. past 1.8, the blades close to whatever aperture you set it at when you take the pic..

  14. #14

    Default Re: Lens name

    Quote Originally Posted by J-Chan View Post
    what do you mean by over 1.8? the lens can't physically open up its aperture any further past f/1.8, so it stops at f/1.8 if you turn the dial in your cam..

    if you mean a larger no. past 1.8, the blades close to whatever aperture you set it at when you take the pic..
    Okae! i got it. Thanks alot guys for your replies and pms. It realli made me understand from all ur explanations. I'm a slow learner so need more time to absorb.

  15. #15
    Member akszaksz's Avatar
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    Default Re: Lens name


    If you have an eye (even two) you'll understand easily the concept of aperture: an eye has an iris that regulates the amount of light that the brain will finally interpret. If it is dark, like in a romantic dinner, the pupil will become bigger to gather more light. No wonder the eyes of your beloved looked stunning. But at a very sunny day, those pupils will need to get reduced to avoid the entrance of extra light. The same goes with a camera, there is a mechanism (diaphragm) that controls the amount of light reaching the sensor.

    The aperture combined with the ISO sensitivity and the shutter speed, the degree of exposure to light is regulated. Now, the thing is that your eyes don't work exactly like your still photographs camera. In your camera there will be a combination of parameters to expose correctly the image: for how long the shutter will be opened, how sensitive the sensor of the camera will be and how big the hole (aperture) that allows light into the sensor will be.

    The lens aperture is usually specified as an f-number. Although it may sound tricky, if the "f" number is small (like f/1.2, f/1.4 or f/1.8) the aperture is very big. If the "f" numbers are higher (e.g. f/11, f/16, f/22) the aperture size is smaller.



    Read up the following to get better understanding:
    http://www.photoaficionado.com/situa.../aperture.html
    http://en.wikipedia.org/wiki/Aperture
    http://www.akkuaphotography.com

  16. #16

    Default Re: Lens name

    Hey really helped me with the simple explanation and showing me images. Thanks!

  17. #17
    Member akszaksz's Avatar
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    Default Re: Lens name

    Quote Originally Posted by xtin88 View Post
    Hey really helped me with the simple explanation and showing me images. Thanks!
    good for ya.

    Now it's time to play around with those settings (Aperture, ShutterSpeed, ISO, etc)
    try it out and learn from it till you can get what you want to get.

    http://www.akkuaphotography.com

  18. #18

    Default Re: Lens name

    yeap practice practice!

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