Page 2 of 2 FirstFirst 12
Results 21 to 32 of 32

Thread: super noob question. is f2.8 = f/2.8??

  1. #21

    Default

    Quote Originally Posted by Noir
    And apart from F-stop, there is something called T-stop too. Know what it is ?
    is that something found on a video camera?

  2. #22

    Default

    Quote Originally Posted by Astin
    Ok, now you go and find out what does the letter "f" stand for?
    (Give you something to do on a boring Thursday afternoon )
    Hey Astin,
    If I recall correctly, the 'f' in f/stop stands for foot-candles right?

    Please correct me if I am wrong.

    Cheers,
    -Michelle-

  3. #23
    Senior Member
    Join Date
    Mar 2002
    Location
    Astin Studio
    Posts
    4,737

    Default

    Quote Originally Posted by mich_2103
    Hey Astin,
    If I recall correctly, the 'f' in f/stop stands for foot-candles right?

    Please correct me if I am wrong.

    Cheers,
    -Michelle-
    Not really lah Michelle.
    According to the legend, (I copied this out)
    "...Willard (Van Dyke) remembered that he proposed "U.S.256," the old system name for f/64. He said that Ansel responded, "U.S. 256 is not good, it sounds like a highway." Willard continued, "He then took a pencil and made a a curving 'f' followed by the dot and 64. The graphics were beautiful and that was that." At first, it was written "Group f.64" in the style of the old aperture notation, but that was soon updated to the new notation with its slash, "Group f/64." To those familiar with Ansel's handwriting, the f in the Group f/64 exhibition invitation appears nearly identical to his own typical, very musical looking f."

    But I think it more or less is a mathematical notation, f stands for "function of" eg f(1/diameter)
    Whats your score in maths?

  4. #24

    Default

    Quoting from a site

    " F-stops vs. T-stops
    When you are calculating exposure, you need to know how much light passes through the lens to the film. The f-stop is a geometric relationship between focal length and aperture and does not take into account how much light is lost within a lens. Each air-to-glass surface within a lens reflects some light. A zoom lens (like the one on the Bolex you will use) can have more than 15 elements and lose a significant amount of light to internal reflections.

    A perfect lens, a lens of 100% transmission, transmits all the light that it gathers with no internal losses. The T-STOP is defined as the equivalent to an f-stop of a perfect lens.

    Thus on a perfect lens, the f-stop and the t-stop are identical. On a lens that lost a full stop in transmission (that is, a 50-percent loss), f/8 would result in the same exposure as T11.
    "

    T-stops are usually found on motion picture lenses to compensate for the loss of light within. However I do have a question, and hope someone is able to shed some light? So are the stop markings found on stills photography lenses already compensated for this light loss, no matter how slight? Thanx!
    Last edited by Noir; 6th May 2004 at 04:29 PM.

  5. #25

    Default

    the t stop is transimssion stop if i recall correct..they say its a more accurate form of f stop

  6. #26
    Senior Member
    Join Date
    Mar 2002
    Location
    Astin Studio
    Posts
    4,737

    Default

    wah, a super noob question turns into a super deep question now, pangz.

  7. #27

    Default

    Quote Originally Posted by Astin
    wah, a super noob question turns into a super deep question now, pangz.
    Ha Ha! Yes Astin. Need to be technically apt to be creatively sound in photography. Let's learn from one another here.

  8. #28
    Member
    Join Date
    Nov 2003
    Location
    Northeast
    Posts
    1,225

    Default

    Quote Originally Posted by Noir
    Quoting from a site

    " F-stops vs. T-stops
    When you are calculating exposure, you need to know how much light passes through the lens to the film. The f-stop is a geometric relationship between focal length and aperture and does not take into account how much light is lost within a lens. Each air-to-glass surface within a lens reflects some light. A zoom lens (like the one on the Bolex you will use) can have more than 15 elements and lose a significant amount of light to internal reflections.

    A perfect lens, a lens of 100% transmission, transmits all the light that it gathers with no internal losses. The T-STOP is defined as the equivalent to an f-stop of a perfect lens.

    Thus on a perfect lens, the f-stop and the t-stop are identical. On a lens that lost a full stop in transmission (that is, a 50-percent loss), f/8 would result in the same exposure as T11.
    "

    T-stops are usually found on motion picture lenses to compensate for the loss of light within. However I do have a question, and hope someone is able to shed some light? So are the stop markings found on stills photography lenses already compensated for this light loss, no matter how slight? Thanx!
    Nope, the F stop for still cameras is the F stop. If it's compensated already, then it would be called the T stop and not the F stop. But as I said earlier, the difference is very slight in todays lenses, with their multicoating, aspherical design, etc. You will loss more light tranmission by slapping a filter over the lens. Anyway, since the camera is situated behind the lens, any light loss will be factored into the metering.

  9. #29

    Default

    Quote Originally Posted by Astin
    wah, a super noob question turns into a super deep question now, pangz.
    i was JUST about to say that!

    what's your score in mind-reading?

  10. #30

    Default

    but it's been a great learning experience for me. do continue the conversation. i'll just sit back and read the info..

    all this is really way outta my league.

  11. #31
    Senior Member
    Join Date
    Mar 2002
    Location
    Astin Studio
    Posts
    4,737

    Default

    No problem. When you become oldbie, you would then explain to the newbie and not scold or laugh at them ok?

  12. #32

    Default

    Quote Originally Posted by Astin
    No problem. When you become oldbie, you would then explain to the newbie and not scold or laugh at them ok?
    sure thing. and i'll always remember to ask them their physics and maths score..

Page 2 of 2 FirstFirst 12

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
  •