F Stop lens question...

Discussion in 'Photography Beginners' Forum' started by Big, Jul 1, 2009.

  1. Big

    Big TPF Noob!

    Joined:
    Apr 22, 2009
    Messages:
    1,228
    Likes Received:
    0
    Location:
    New Hampshire
    Can others edit my Photos:
    Photos NOT OK to edit
    I was wondering why lenses will say f/3.5-5.6 but when you read the specs, it goes all the way to 22 or such...I know what f-stops are but this has been something that has me confused. :scratch:

    Thanks -BIG
     
    Last edited: Jul 1, 2009
  2. JamieR

    JamieR TPF Noob!

    Joined:
    Apr 27, 2009
    Messages:
    320
    Likes Received:
    1
    Can others edit my Photos:
    Photos OK to edit
    I believe it's the maximum aperture. SO say you have the Canon EF-S 18-55mm f/3.5-5.6, the maximum aperture at 18mm would be the f/3.5, and the maximum aperture at 55mm would me f/5.6.

    I'm sure someone will correct me if I'm wrong, i only own a prime lens!
     
  3. Christie Photo

    Christie Photo No longer a newbie, moving up!

    Joined:
    Jan 7, 2005
    Messages:
    7,006
    Likes Received:
    67
    Location:
    Kankakee, IL
    That's exactly right.

    -Pete
     
  4. Big

    Big TPF Noob!

    Joined:
    Apr 22, 2009
    Messages:
    1,228
    Likes Received:
    0
    Location:
    New Hampshire
    Can others edit my Photos:
    Photos NOT OK to edit
    Thanks guys. I guess that's why when I'm in manual mode on my P&S that when I zoom in the aperture is automatically raised making me have to use a slower shutter speed... I just thought that if 22 was the max aperture that it would say f/3.5-22 instead of just to 5.6.
     
  5. JamieR

    JamieR TPF Noob!

    Joined:
    Apr 27, 2009
    Messages:
    320
    Likes Received:
    1
    Can others edit my Photos:
    Photos OK to edit
    22 in the minimum aperture.
     
  6. Big

    Big TPF Noob!

    Joined:
    Apr 22, 2009
    Messages:
    1,228
    Likes Received:
    0
    Location:
    New Hampshire
    Can others edit my Photos:
    Photos NOT OK to edit
    Thanks haha I get it confused once in a while... :banghead:
     
  7. bigboi3

    bigboi3 TPF Noob!

    Joined:
    Apr 1, 2009
    Messages:
    599
    Likes Received:
    6
    Location:
    Pittsburg, CA
    Can others edit my Photos:
    Photos NOT OK to edit
    +1
     
  8. Dwig

    Dwig TPF Noob!

    Joined:
    Mar 11, 2009
    Messages:
    1,261
    Likes Received:
    0
    Location:
    Key West FL
    Can others edit my Photos:
    Photos NOT OK to edit
    One way to keep it straight is to always write the number correctly. F/stops should always be written as either fractions (f/32) or ratios (1:2.0) since that's what they are.

    The "f" in the fraction notation means "focal length" and "f/8" means the diameter of the effective aperture (not necessarily the mechanical iris) is equal to the focal length divided by eight. And as everyone who passed 4th grade math knows, one quarter (1/4 or f/4) is smaller than one half (1/2 or f/2).

    The confusion comes when people write only the denominator of the fraction (8 or 22) instead of the whole fraction (f/8 or f/22), either out of laziness or when space is limited (digital camera displays or f/stop rings). They should never be written with the "f" capitalized, except at the beginning of a sentence, or without the slash, "/".
     

Share This Page

Search tags for this page

can you get a fstop 1.4 with a 3.5-22 lens