Auto-Focus failed, but still took the picture.

Discussion in 'Technical Troubleshooting' started by Tonytee, Apr 17, 2021.

  1. Tonytee

    Tonytee Well-Known Member Site Supporter

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    Using my Canon EOS 7D MkII with a Canon EF-S 55~250mm, IS, STM lens while shooting a flower, the auto-focus failed to get the subject in proper focus, even though the in focus indicator light was on. I took the snap and sure enough the subject was obviously out of focus. I checked and the battery level indicator was clearly at 91%, so that was not a problem. After checking the battery power level, I resumed shooting and everything seemed to be in order. I will post the image here. Thnx for the assistance. Tony 7M1A2843.JPG
     

  2. Caladina

    Caladina Well-Known Member

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    have you got the image with the focus square imbeded to show it was focused on the flower
     
  3. Tonytee

    Tonytee Well-Known Member Site Supporter

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    7M1A2845.JPG
    Unfortunately no, it does show the focus grid, however when I bring up the image, the grid disappears. Thnx a bunch. :) Tony
     
  4. Caladina

    Caladina Well-Known Member

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    when you put the image up with the boxes take a picture of it with your camera on the computer screen, i had to do that with my focus boxes when i wanted to show them.
    As your smudge box is a dslr could it be a one off mirror stick
     
  5. Tonytee

    Tonytee Well-Known Member Site Supporter

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  6. Tonytee

    Tonytee Well-Known Member Site Supporter

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    Had to do a Screen Shot. Judging from the two red squares, it appears to be a misfocus. I do not know how that could happen. Thnx. Tony
     
  7. Caladina

    Caladina Well-Known Member

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    yeah i was thinking it caught the rock or that line just looking at the image, i didn't want to start guessing at other stuff till we saw the evidence.
    cameras misfocus, it probably saw the sharper detail in the rock and foliage as a preferred target.
    one of the reasons i like single point box,
     
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  8. Tonytee

    Tonytee Well-Known Member Site Supporter

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    Great. I have set up for Single Point Focus, so will have to see what transpires. Thnx for the assistance. Admittedly, for me anyway, Canon's Auto-Focus features seem to be quite confusing. :( Tony
     
  9. Caladina

    Caladina Well-Known Member

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    watch some youtubes on canon focus systems, i bet its that bloody squirrel getting you all flustered with its running around and moving, you were fine when you only had tulips to worry about :p
     
  10. Tonytee

    Tonytee Well-Known Member Site Supporter

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    I believe what I will do is to contact Canon and inquire if I may send them the screen shot and explain the situation, they may be able to assist me. I know you mentioned that the cameras sometimes misfocus, however the AF & IS systems are incorporated into the lens. I do have a spare lens (same) and will work with that for a while and see if the same situation re-occurs. If so, then it is the camera as I cannot imagine two lenses failing. Thnx for the info and the helpful suggestions. Tony :)
     
  11. Caladina

    Caladina Well-Known Member

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    there isn't any thing wrong with the image, the camera has focused on the items in the red box and taken those and they are the items in focus, i don't see anything of concern here
    if the red squares were on the out of focus flower then you'd have a problem.
    a case of the camera picking a different subject to what you had in mind, happens alot with birds in trees or small mammals on the ground.

    also as you used the multi point focus you have given the camera free reign to pick anything in those black squares to focus on, its going to pick the item with the best contrast.
    its ok using multi point on a bird in the sky as there is just the bird to attract the af, if the bird is in front of trees the af can sometimes think the trees are what you want to take a smudge of.
     
    Last edited: Apr 19, 2021
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  12. Tonytee

    Tonytee Well-Known Member Site Supporter

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    Okay, that is very helpful and presents a clear understanding. Again, many thanks. Tony :)
     

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