Results 1 to 5 of 5

Thread: F2.8 vs F4 flash photos

  1. #1
    Member
    Join Date
    Jun 2003
    Location
    London, United Kingdom
    Posts
    596

    Question F2.8 vs F4 flash photos

    With a flash in low light situation (wedding dinner example. i am NOT wedding photographer), will a f2.8 lens achieve brighter background?

    My setup is Dynax 5, Press 800, minolta 70-200/4, Metz 32Mz2, exposure usually F4 1/125s or F4 1/90s. Flash set on TTL, direct flash, no bounce. Mostly firing at the 200mm range (far far away from the B&G.) Previous tests with 1/60, 1/30 got some handshake....

  2. #2

    Default

    Quote Originally Posted by alvin
    With a flash in low light situation (wedding dinner example. i am NOT wedding photographer), will a f2.8 lens achieve brighter background?

    My setup is Dynax 5, Press 800, minolta 70-200/4, Metz 32Mz2, exposure usually F4 1/125s or F4 1/90s. Flash set on TTL, direct flash, no bounce. Mostly firing at the 200mm range (far far away from the B&G.) Previous tests with 1/60, 1/30 got some handshake....
    Yes but the picture will not be sharp
    Canon 10D/550D /Sigma 17-50mm/Sigma 30mm/Canon 50mm/Sigma 85mm

  3. #3
    Senior Member
    Join Date
    Jan 2002
    Location
    Behind a lens
    Posts
    2,312

    Default

    With a larger aperture or a slower shutter speed, you will achieve a brighter background.

    ie. F4 -> F1.8
    ie. 1/125s -> 1/60

    With aperture being bigger, your dof will be narrower.
    With shutter speed being slower, motion blur and camera shake might be a problem.

    If you are using TTL flash, the recycle time will be lesser too.

    I dun really get what tweakmax means by the pic will not be sharp. Perhaps he is assuming the lens will not be sharp at wide open. Some better lens have pretty decent sharpness even if wide open. At least it would show much in a 4R print.

  4. #4

    Default

    Quote Originally Posted by binbeto
    With a larger aperture or a slower shutter speed, you will achieve a brighter background.

    ie. F4 -> F1.8
    ie. 1/125s -> 1/60

    With aperture being bigger, your dof will be narrower.
    With shutter speed being slower, motion blur and camera shake might be a problem.

    If you are using TTL flash, the recycle time will be lesser too.

    I dun really get what tweakmax means by the pic will not be sharp. Perhaps he is assuming the lens will not be sharp at wide open. Some better lens have pretty decent sharpness even if wide open. At least it would show much in a 4R print.
    yup this is what i mean...
    Canon 10D/550D /Sigma 17-50mm/Sigma 30mm/Canon 50mm/Sigma 85mm

  5. #5
    Member
    Join Date
    Jun 2003
    Location
    London, United Kingdom
    Posts
    596

    Default

    Thanks dudes!

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
  •