ISO question

Discussion in 'Digital Photography' started by DeanB, Jul 10, 2007.

  1. DeanB

    DeanB Guest

    Does changing the ISO value on a DSLR change a physical property of
    the sensor (voltage?) to make it more sensitive? Or is this just a
    software-only effect?

    Camera I have in mind is the Nikon D2Hs, which is a CMOS.

    Thanks!

    Dean
     
    DeanB, Jul 10, 2007
    #1
    1. Advertising

  2. DeanB

    Bob Williams Guest

    DeanB wrote:
    > Does changing the ISO value on a DSLR change a physical property of
    > the sensor (voltage?) to make it more sensitive? Or is this just a
    > software-only effect?
    >
    > Camera I have in mind is the Nikon D2Hs, which is a CMOS.
    >
    > Thanks!
    >
    > Dean
    >

    Changing the ISO Number changes the gain in the amplifier.
    Increasing the amplifier gain introduces, some additional noise and
    therefore decreases the S/N ratio of the resultant image.
    "There ain't no free lunch".
    Bob Williams
     
    Bob Williams, Jul 10, 2007
    #2
    1. Advertising

  3. On Jul 10, 2:47 am, DeanB <> wrote:
    > Does changing the ISO value on a DSLR change a physical property of
    > the sensor (voltage?) to make it more sensitive? Or is this just a
    > software-only effect?
    >
    > Camera I have in mind is the Nikon D2Hs, which is a CMOS.
    >
    > Thanks!
    >
    > Dean


    No. The chip voltages must be carefully controlled over a narrow
    range of tolerance. Changing the ISO makes changes to the file AFTER
    reading out the CCD chip. It does nothing to the chip, or the
    information while it is in the chip. One can increase the gain of the
    analog preamp, or diddle with levels in the A/D converter.
     
    Don Stauffer in Minnesota, Jul 10, 2007
    #3
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. JD

    How do you convert a CD ISO to DVD ISO?

    JD, Aug 20, 2004, in forum: Computer Support
    Replies:
    9
    Views:
    29,397
  2. Bill Smith
    Replies:
    1
    Views:
    905
    DaveJ
    Aug 1, 2003
  3. Salem Derisavi

    Figuring out ISO settings in Auto ISO mode

    Salem Derisavi, Sep 28, 2003, in forum: Digital Photography
    Replies:
    3
    Views:
    1,574
    Andrew McDonald
    Sep 29, 2003
  4. Georgette Preddy

    Is Sigma's SD10 at ISO 1600 better than Canon's 1Ds at ISO 100?

    Georgette Preddy, Jul 11, 2004, in forum: Digital Photography
    Replies:
    14
    Views:
    728
    Randall Ainsworth
    Jul 15, 2004
  5. cohibakid

    rebel 300d iso 100 vs nikon d70 iso 200

    cohibakid, Jul 14, 2004, in forum: Digital Photography
    Replies:
    4
    Views:
    610
    David J. Littleboy
    Jul 15, 2004
Loading...

Share This Page