Results 1 to 9 of 9

Thread: Check on AF accuracy

  1. #1

    Default Check on AF accuracy

    Hi guys!

    I went to a concert on last night and was happily snapping pictures away on my 85 1.8 and 28 1.8.

    While browsing through the pictures I realise that most of the pictures are a little bit soft, but very acceptable.

    I switched to Live View mode and all the pictures came out tack sharp.

    So is there something wrong with the AF sensor? Im using center point all the way.

    Thanks for the help!
    Canon 6D | Canon 450D + Grip | EF 28 F1.8 | EF 85 F1.8 | Nissin 866 Flash

  2. #2
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: Check on AF accuracy

    Quote Originally Posted by JJLoke View Post
    Hi guys!

    I went to a concert on last night and was happily snapping pictures away on my 85 1.8 and 28 1.8.

    While browsing through the pictures I realise that most of the pictures are a little bit soft, but very acceptable.

    I switched to Live View mode and all the pictures came out tack sharp.

    So is there something wrong with the AF sensor? Im using center point all the way.

    Thanks for the help!
    maybe you can post some of your blur pics, and a sample of your sharp pics. With exif info.. so we can take a look and figure out why?

  3. #3

    Default Re: Check on AF accuracy

    I have uploaded 2 photos on Flickr

    the sharper one is using liveview and the oof is using center point AF.

    http://www.flickr.com/photos/5615502...n/photostream/

    Here is the 2 photo data:

    Canon 85mm f1.8 USM

    Canon EOS 450D

    Shutter Speed - 1/320 sec.
    Lens Aperture - F/2.2
    ISO Speed - ISO-1600
    Metering Mode - Partial
    Exposure Program - Manual
    Last edited by JJLoke; 21st November 2010 at 01:36 PM.
    Canon 6D | Canon 450D + Grip | EF 28 F1.8 | EF 85 F1.8 | Nissin 866 Flash

  4. #4
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: Check on AF accuracy

    Quote Originally Posted by JJLoke View Post
    I have uploaded 2 photos on Flickr

    the sharper one is using liveview and the oof is using center point AF.

    http://www.flickr.com/photos/5615502...n/photostream/

    Here is the 2 photo data:

    Canon 85mm f1.8 USM

    Canon EOS 450D

    Shutter Speed - 1/320 sec.
    Lens Aperture - F/2.2
    ISO Speed - ISO-1600
    Metering Mode - Partial
    Exposure Program - Manual
    There is a big chance your lens AF accuracy is off (front focusing or back focusing).

    You should confirm this by testing your lens on a focus test chart (download here).

    If there indeed is a problem, send it into CSC for a calibration.

  5. #5

    Default Re: Check on AF accuracy

    I have send down my lens for calibration once and the technician reset the lens.

    If its lens problem, shouldnt the live view be oof as well?
    Canon 6D | Canon 450D + Grip | EF 28 F1.8 | EF 85 F1.8 | Nissin 866 Flash

  6. #6
    Member
    Join Date
    Apr 2006
    Location
    Singapore
    Posts
    73

    Default Re: Check on AF accuracy

    i think it has something to do with where you set your focus point as well.
    1D3, EF 16-35mm F2.8L II, EF 24-70mm F2.8L, EF 70-200mm F2.8L IS, Speedlite 580EX II, 420EX

  7. #7

    Default Re: Check on AF accuracy

    Its center point AF all the way

    If that is unreliable in low light, the rest wun do much better
    Canon 6D | Canon 450D + Grip | EF 28 F1.8 | EF 85 F1.8 | Nissin 866 Flash

  8. #8

    Default Re: Check on AF accuracy

    At F2.2 the DOF is quite shallow and the margin for AF error if quite big. If I were to guess, I would say it could be the way you hold to cam. Prolly when using liveview, your stance is a litlle bit more steady (less movement).... I'm just guessing here.
    |SonyA700|T180mmf3.5|M70-210mmf4|S30mmf1.4|T17-50mmf2.8|T90mmf2.8|M5600hsdX2|

  9. #9
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: Check on AF accuracy

    Quote Originally Posted by JJLoke View Post
    I have send down my lens for calibration once and the technician reset the lens.

    If its lens problem, shouldnt the live view be oof as well?
    LV and viewfinder uses different AF sensors.

    For LV, it will do contrast detection, and that contrast detection is based on the image captured on the sensor. So definitely no problem in LV.

    you need to bring your lens and camera into the service center.

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
  •