Results 1 to 12 of 12

Thread: I am not sure if i am asking the correctly. But I would like to learn how to calculat

  1. #1
    Member
    Join Date
    May 2009
    Location
    Singapore
    Posts
    21

    Default I am not sure if i am asking the correctly. But I would like to learn how to calculat

    Hi Guys!!

    I'm a neophyte here. I just found this question from a particular but no answer..

    I found this question interesting..need your professional advice.

    this is the question:

    I am not sure if i am asking the correctly. But I would like to learn how to calculate new shutter speed base on F stop increment or decrement? for example, 1/60 after 1-stop decrement = ?.

  2. #2
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    very simple

    + one stop is double,

    - one stop is half.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  3. #3
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    30 sec
    15 sec
    8 sec
    4 sec
    2 sec
    1 sec
    1/2 sec
    1/4 sec
    1/8 sec
    1/15 sec
    1/30 sec
    1/60 sec
    1/125 sec
    1/250 sec
    1/500 sec
    1/1000 sec
    1/2000 sec
    1/4000 sec
    1/8000 sec

    get it?
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  4. #4
    Member
    Join Date
    May 2009
    Location
    Singapore
    Posts
    21

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    Thanks for the quick reply bro!! yeah i got it but how about the aperture? I've read some articles that there are some settings which is equal exposure to the different settings, in relation with shutter+apperture. I'm confused...

  5. #5
    Senior Member +evenstar's Avatar
    Join Date
    Jan 2004
    Location
    Singapore / United Kingdom
    Posts
    5,655

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    e.g.

    1/60s, f4 = 1/30s, f5.6 = 1/15s, f8

  6. #6
    Senior Member
    Join Date
    Jun 2003
    Location
    Singapore, Bedok
    Posts
    1,785

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    Quote Originally Posted by macasuero View Post
    Thanks for the quick reply bro!! yeah i got it but how about the aperture? I've read some articles that there are some settings which is equal exposure to the different settings, in relation with shutter+apperture. I'm confused...
    In photography lingo, one stop is half or double the amount of light.

    Opening the shutter twice as long increases the exposure by one stop, reducing the shutter speed by half decreases the exposure by one stop.

    Opening the aperture to twice/half its area lets in twice or half the amount of light, and hence increases/decreases the exposure by one stop.

    The f-stop number is the ratio of the lens' focal length to its aperture. Eg f4 means the aperture's radius is 1/4 of its focal length, f2 means the radius is half the focal length. Every change of 1.414x (square root 2) in the f-number changes the exposure by one stop. f2.0 to f1.4 is an increase of one stop, f2.0 to f2.8 is a decrease of one stop, also known as "stopping down".

    For any particular exposure, changing the shutter speed by n stops and changing the aperture by the same number of stops in the "opposite direction" results in the same exposure. For example, f1.4-1/4s is the same exposure as f2.0-1/2s (stopped down), and is also the same exposure as f1.0-1/8s.

  7. #7
    Senior Member
    Join Date
    Jul 2006
    Location
    Clementi
    Posts
    10,596

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    List of full f/stops:

    f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/44, f/64 (and I don't think you'll see anything beyond this on a SLR system anyways)

    There are intermediate f/stops, depending on your camera. They may be in 1/3 stops or 1/2 stops, for instance

    1/3-stops: f/2, f/2.2, f/2.5, f/2.8, or
    1/2-stops: f/4, f/4.5, f/5.6

  8. #8

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    What Catchlights said.

    Also, Google EV or Exposure Value and look at the old school EV/Exposure meter dials. That's everything ST1100 said at a glance.

  9. #9
    Member
    Join Date
    May 2009
    Location
    Paris (FRANCE)
    Posts
    138

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    This will help :


  10. #10

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    Quote Originally Posted by macasuero View Post
    I just found this question from a particular but no answer..
    Did you try searching? Your question is the very basics of exposure, and is detailed, described and in many cases even charted all over the web and in many photography books.
    Alpha

  11. #11
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,902

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    just for the fun......

    f/1, f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, f/22, f/32, f/45, f/64,

    f90
    f128
    f180
    f256
    f360
    f512
    f720

    FIY, after f90, most like you will only see pinhole cameras has such small aperture.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  12. #12
    Moderator Octarine's Avatar
    Join Date
    Jan 2008
    Location
    Pasir Ris
    Posts
    12,390

    Default Re: I am not sure if i am asking the correctly. But I would like to learn how to calc

    Quote Originally Posted by macasuero View Post
    Thanks for the quick reply bro!! yeah i got it but how about the aperture? I've read some articles that there are some settings which is equal exposure to the different settings, in relation with shutter+apperture. I'm confused...
    Read this Newbies Guide first, no point asking endless questions if you don't know much about the very basics. It needs 3 parameters to define exposure: shutter speed, aperture and ISO. Changing one requires also changing the other one or two in order to keep the exposure correct (correct amount of light to capture the image).

Bookmarks

Posting Permissions

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