Canon G5 focusing issues (dim light)

Discussion in 'Digital Photography' started by GW, Dec 5, 2003.

  1. GW

    GW Guest

    My Canon G5 exhibits odd focusing inconsistency: in dim light it
    focuses fine with the lens at the wide end, but terribly with the lens
    at the long (tele) end. (Note: I'm using a tripod, so this isn't
    telephoto enhanced camera shake). In fact, as I watch the LCD screen
    while the camera autofocuses (which I can do, as it's dim light, not
    darkness), I can see it briefly stop at what looks like good focus,
    but then the mechanism engages again and takes it out of focus, where
    it stays for the photo. Yet this doesn't occur at the wide angle end.
    Has anyone else seen this? Is this a built in limitation, or a
    defect of this particular camera? Thanks for any advice.

    GW
    GW, Dec 5, 2003
    #1
    1. Advertising

  2. GW

    Zol. Guest

    I think this is normal as the focus depends on the contrast of an object and in very dim
    lighting conditions such contrast is more difficult to resolve - best to use the manual
    focus in these cases ... Zol.


    "GW" <> wrote in message
    news:...
    > My Canon G5 exhibits odd focusing inconsistency: in dim light it
    > focuses fine with the lens at the wide end, but terribly with the lens
    > at the long (tele) end. (Note: I'm using a tripod, so this isn't
    > telephoto enhanced camera shake). In fact, as I watch the LCD screen
    > while the camera autofocuses (which I can do, as it's dim light, not
    > darkness), I can see it briefly stop at what looks like good focus,
    > but then the mechanism engages again and takes it out of focus, where
    > it stays for the photo. Yet this doesn't occur at the wide angle end.
    > Has anyone else seen this? Is this a built in limitation, or a
    > defect of this particular camera? Thanks for any advice.
    >
    > GW
    Zol., Dec 5, 2003
    #2
    1. Advertising

  3. GW

    Ed Ruf Guest

    Ed Ruf, Dec 5, 2003
    #3
  4. GW

    Ed Ruf Guest

    On 5 Dec 2003 04:11:41 -0800, in rec.photo.digital
    (GW) wrote:

    >My Canon G5 exhibits odd focusing inconsistency: in dim light it
    >focuses fine with the lens at the wide end, but terribly with the lens
    >at the long (tele) end. (Note: I'm using a tripod, so this isn't
    >telephoto enhanced camera shake). In fact, as I watch the LCD screen
    >while the camera autofocuses (which I can do, as it's dim light, not
    >darkness), I can see it briefly stop at what looks like good focus,
    >but then the mechanism engages again and takes it out of focus, where
    >it stays for the photo. Yet this doesn't occur at the wide angle end.
    > Has anyone else seen this? Is this a built in limitation, or a
    >defect of this particular camera? Thanks for any advice.


    This is pretty normal. The f-number of the lens is not constant and it
    is higher at the longer focal lengths.
    ________________________________________________________
    Ed Ruf Lifetime AMA# 344007 ()
    http://members.cox.net/egruf
    See images taken with my CP-990 and 5700 at
    http://members.cox.net/egruf-digicam
    Ed Ruf, Dec 5, 2003
    #4
  5. GW

    VT Guest

    At the telephoto end the max aperture is f/3 vs. at the wide-angle end
    of f/2 - that's just over 1 stop less light it's letting through - so
    when the light is low and the focus-assist light is just marginal for
    the wide-angle end's f/2 - the smaller apperture of the telephoto end
    will then cause problems for the auto focus.

    ie: the light is too low and the focus-assist light is not bright
    enough or provide enough contrast for the camera to focus.

    --
    Vincent
    remove CLOTHES for e-mail

    http://UnknownVincent.cjb.net/
    VT, Dec 5, 2003
    #5
  6. GW

    Guest

    On 5 Dec 2003 04:11:41 -0800, (GW) wrote:

    >My Canon G5 exhibits odd focusing inconsistency: in dim light it
    >focuses fine with the lens at the wide end, but terribly with the lens
    >at the long (tele) end. (Note: I'm using a tripod, so this isn't
    >telephoto enhanced camera shake). In fact, as I watch the LCD screen
    >while the camera autofocuses (which I can do, as it's dim light, not
    >darkness), I can see it briefly stop at what looks like good focus,
    >but then the mechanism engages again and takes it out of focus, where
    >it stays for the photo. Yet this doesn't occur at the wide angle end.
    > Has anyone else seen this? Is this a built in limitation, or a
    >defect of this particular camera? Thanks for any advice.
    >
    >GW


    Mine focuses pretty badly at the tele end, even in good light, and
    interior lighting is a waste of time. I use manual focus a lot in
    these situations.

    MJ
    , Dec 7, 2003
    #6
    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. Roger

    Low Light Focusing with EOS Cameras

    Roger, Aug 6, 2003, in forum: Digital Photography
    Replies:
    2
    Views:
    436
    Todd Walker
    Aug 7, 2003
  2. DigitalCameraBasics

    To Canon 10D owners: What has Canon told YOU about focusing "issues"?

    DigitalCameraBasics, Nov 3, 2003, in forum: Digital Photography
    Replies:
    9
    Views:
    451
    Lionel
    Nov 16, 2003
  3. Joe B.

    Canon Pwershot S50- focusing light switchable?

    Joe B., Jan 19, 2004, in forum: Digital Photography
    Replies:
    0
    Views:
    314
    Joe B.
    Jan 19, 2004
  4. Dale Bricker

    Looking for good camera for dim indoor light

    Dale Bricker, May 24, 2004, in forum: Digital Photography
    Replies:
    2
    Views:
    337
    Lionel
    May 25, 2004
  5. More Canon 20d focusing issues

    , Sep 27, 2005, in forum: Digital Photography
    Replies:
    14
    Views:
    476
    Randall Ainsworth
    Oct 2, 2005
Loading...

Share This Page