Focus Issues...

mushymushy Registered Users Posts: 643 Major grins
edited March 6, 2007 in Cameras
I recently spent a month in Thailand which I'll post in journeys shortly. When I got home I noticed a larger than normal amount of shots out of focus. Mainly using the 10-22 and a 17-85mm lens. I did notice the 10-22 does alot of searching when you shoot to infinity and all too often it would stay out of focus. Do these sort of issues lie with the lens or the camera body itself.
Any help would be greatly appreciated :scratch
May I take your picture?

Comments

  • ziggy53ziggy53 Super Moderators Posts: 24,078 moderator
    edited March 4, 2007
    mushy wrote:
    I recently spent a month in Thailand which I'll post in journeys shortly. When I got home I noticed a larger than normal amount of shots out of focus. Mainly using the 10-22 and a 17-85mm lens. I did notice the 10-22 does alot of searching when you shoot to infinity and all too often it would stay out of focus. Do these sort of issues lie with the lens or the camera body itself.
    Any help would be greatly appreciated headscratch.gif

    Look for consistant errors like front-focus/back-focus. If you see a lot of front-focus error (for example), that may be correctable. Samples and EXIF would help determine the problem and its extent.

    It could be technique or subject based. We would have to see some samples to guess more accurately.

    Filters can cause focus problems, and in my experience, the wider the lens (shorter the focal length) the more likely focus is to be affected by a filter.

    Focus problems with more than one lens tends to be camera related, but technique can greatly impact the results as well and improper technique can affect multiple lenses (obviously.)
    ziggy53
    Moderator of the Cameras and Accessories forums
  • mushymushy Registered Users Posts: 643 Major grins
    edited March 5, 2007
    ziggy53 wrote:
    Look for consistant errors like front-focus/back-focus. If you see a lot of front-focus error (for example), that may be correctable. Samples and EXIF would help determine the problem and its extent.

    It could be technique or subject based. We would have to see some samples to guess more accurately.

    Filters can cause focus problems, and in my experience, the wider the lens (shorter the focal length) the more likely focus is to be affected by a filter.

    Focus problems with more than one lens tends to be camera related, but technique can greatly impact the results as well and improper technique can affect multiple lenses (obviously.)

    Cheers Ziggy for the quick reply. Most of the issues relate to the 10-22 and are shooting landscapes where you'll see the lens focus pretty quick and then step out of focus before you take the shot. I'll upload an example when I get home. The filters thought made some sense but I don't have one on the lens in question. It was also a full range of low light to broad day light photo's. Mainly shot on Aperture priority with a minimu of 125th shutter speed.
    May I take your picture?
  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited March 5, 2007
    Focus setting wasn't AI Servo, was it?
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • mushymushy Registered Users Posts: 643 Major grins
    edited March 5, 2007
    wxwax wrote:
    Focus setting wasn't AI Servo, was it?

    most probably was, as this is the focus setting I use most of the time as I usually shot sports or am tracking some sort of nature.
    May I take your picture?
  • wxwaxwxwax Registered Users Posts: 15,471 Major grins
    edited March 5, 2007
    mushy wrote:
    most probably was, as this is the focus setting I use most of the time as I usually shot sports or am tracking some sort of nature.
    That probably explains your problems, then. AI Servo will continue to hunt when you try to shoot static objects. It's *not* a good setting to use for anything but tracking moving objects, in my experience. Been there, done that, took me a while to figure out why my focus wouldn't settle down. 11doh.giflol3.gif
    Sid.
    Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam
    http://www.mcneel.com/users/jb/foghorn/ill_shut_up.au
  • gusgus Registered Users Posts: 16,209 Major grins
    edited March 5, 2007
    wxwax wrote:
    That probably explains your problems, then. AI Servo will continue to hunt when you try to shoot static objects. It's *not* a good setting to use for anything but tracking moving objects, in my experience. Been there, done that, took me a while to figure out why my focus wouldn't settle down. 11doh.giflol3.gif
    Thats odd because AI servo is all i ever use on both cameras & i never have any issues at all ne_nau.gif
  • mushymushy Registered Users Posts: 643 Major grins
    edited March 6, 2007
    gus wrote:
    Thats odd because AI servo is all i ever use on both cameras & i never have any issues at all ne_nau.gif

    DOH!!
    I read Wxwax's response I went 'wicked' problem solved! then scrolled further down and you go throw some new doubt into the equationne_nau.gif

    Cheers all for the fast responses, will go away now and do some trialling between the 2 focus modes and see if one works better than the other.

    Was only joking Gus btw, all input is always appreciatedthumb.gif
    May I take your picture?
  • gusgus Registered Users Posts: 16,209 Major grins
    edited March 6, 2007
    mushy wrote:
    DOH!!
    I read Wxwax's response I went 'wicked' problem solved! then scrolled further down and you go throw some new doubt into the equationne_nau.gif
    Mate honestly i know stuff all about 'how to'. Follow waxy & give it a try.
  • claudermilkclaudermilk Registered Users Posts: 2,756 Major grins
    edited March 6, 2007
    Another thought: are you using a specific focus point or allowing the 20D to pick them? I know I tripped myself up a couple of times as I typically lock on the center AF point for my theater shoots. Doesn't work so well on landscapes where that's looking a a nice blue sky--lens racks from end to end looking for contrast.:thwak11doh.gif
    Chris
    http://www.chrislaudermilkphoto.com/
  • slapshotslapshot Registered Users Posts: 104 Major grins
    edited March 6, 2007
    mushy wrote:
    I recently spent a month in Thailand which I'll post in journeys shortly. When I got home I noticed a larger than normal amount of shots out of focus. Mainly using the 10-22 and a 17-85mm lens. I did notice the 10-22 does alot of searching when you shoot to infinity and all too often it would stay out of focus. Do these sort of issues lie with the lens or the camera body itself.
    Any help would be greatly appreciated headscratch.gif

    Probably just need to get used to shooting the 10-22. For the longest time I shot only sports with a Nikon 70-200. Then I got the 12-24 to shoot landscapes. First couple of outings the focus was off...I nearly returned the lens. Then I realized it was technique and getting used to the lens. It's very different shooting the wide angle. The 70-200 VR is much more forgiving, the 12-24 I have to really pay attention to technique.
  • mushymushy Registered Users Posts: 643 Major grins
    edited March 6, 2007
    slapshot wrote:
    Probably just need to get used to shooting the 10-22. For the longest time I shot only sports with a Nikon 70-200. Then I got the 12-24 to shoot landscapes. First couple of outings the focus was off...I nearly returned the lens. Then I realized it was technique and getting used to the lens. It's very different shooting the wide angle. The 70-200 VR is much more forgiving, the 12-24 I have to really pay attention to technique.

    Cheers Claudermilk and Slapshot for two more things too look into, I was also close to taking the camera and lens in for a service but instead will spend the weekend experimenting and see what I come up with thumb.gif
    May I take your picture?
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