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Thread: Out of focus image

  1. #1

    Default Out of focus image

    Hi, I'm starting a separate thread for another image which I have question on.

    http://jksim.multiply.com/photos/hi-...hoto%2F10%2F12

    ========================
    Shooting Mode: Manual Exposure
    Tv: 1/500
    Av: 8.0
    ISO Speed: 100
    Focal Length 135mm
    White Balance: Auto
    ========================

    I'm using my one and only lense. A Canon 28 - 135mm with "IS" enabled. Not the best exposure for this shot but am pretty puzzled why did this image of the cat go out of focus (Not sharp) even when I did a Auto Focus dead centre at the nose of the cat.

    QUESTIONS:
    1) Does it have to do with my aperture setting of f8 @ focal length 135mm?
    2) I read that all subject at maximum focal length will have shallow DoF. Is that true for this image?

    I've been shooting cats around my neighbourhood but seems like most of the shots are not exactly sharp.

  2. #2
    Moderator ortega's Avatar
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    Default Re: Out of focus image

    it seems that your point of focus is behind the cat and not on the cat

  3. #3

    Default Re: Out of focus image

    I kind of notice. But.... the focus point shown in my camera was on the nose of the cat. That is why I'm puzzled by this image. Any ideas.....anyone?

  4. #4

    Default Re: Out of focus image

    Quote Originally Posted by Owl07 View Post
    Hi, I'm starting a separate thread for another image which I have question on.

    http://jksim.multiply.com/photos/hi-...hoto%2F10%2F12

    ========================
    Shooting Mode: Manual Exposure
    Tv: 1/500
    Av: 8.0
    ISO Speed: 100
    Focal Length 135mm
    White Balance: Auto
    ========================

    I'm using my one and only lense. A Canon 28 - 135mm with "IS" enabled. Not the best exposure for this shot but am pretty puzzled why did this image of the cat go out of focus (Not sharp) even when I did a Auto Focus dead centre at the nose of the cat.

    QUESTIONS:
    1) Does it have to do with my aperture setting of f8 @ focal length 135mm?
    2) I read that all subject at maximum focal length will have shallow DoF. Is that true for this image?

    I've been shooting cats around my neighbourhood but seems like most of the shots are not exactly sharp.
    theres pretty much only 2 possibilities. user error or camera error.

    if we take u out of the equation, maybe your lens is backfocusing hence the focus was behind rather than on the cat.

    when u use f/8 on all lens, u would not be looking at creating a shallow dof for your pic. rather u are trying to make everything in the picture sharp.

  5. #5
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    Default Re: Out of focus image

    Another possibility is you are too near the subject. Check the minimum focusing distance of your lens.

  6. #6
    Senior Member sammy888's Avatar
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    Default Re: Out of focus image

    Quote Originally Posted by Owl07 View Post
    I kind of notice. But.... the focus point shown in my camera was on the nose of the cat. That is why I'm puzzled by this image. Any ideas.....anyone?

    I don't think so leh heheh... if your auto AF mode is set to the center point of your viewfinder, the cat's nose is not in the center of this picture you posted.(unless you crop it lah) I downloaded it to check. heheh

    If I look at the center of the photo frame, your center is at the cat's belly. The contrast around the cat's body (ginger/ orange colour light strip fur) is not high enough..I am wondering if your AF was having a hard time picking a focus. Or did you focus on the nose, lock the AF and then recompose your shot?

    But I notice that the concrete ground has very contrasty line ruts just behind the cat. I am suspecting your AF picked that over the cat's body as it has better constrast for tracking. I saw that you shot this at 135mm length so were you woobly abit? hehe.. Shot at 1/500 speed slight moving abit might not register any blur. And as you click your shutter ...the AF was still focusing on the line behind as you start to center your wooble back to the cat's belly in the middle
    Last edited by sammy888; 9th January 2008 at 11:39 PM.

  7. #7

    Default Re: Out of focus image

    Possibility is focussing inaccuracy. Is it constand among all picture? If it is its a focusing problem. Send in for calibration. Else is actually a random error due to insufficient contrast. Anyway can tell your focus is behind the cat and quite a significant amount as you are usign f8 where ur depth of field is quite large
    Last edited by zerartul; 9th January 2008 at 11:43 PM.

  8. #8
    Senior Member sammy888's Avatar
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    Default Re: Out of focus image

    Quote Originally Posted by OCP View Post
    Another possibility is you are too near the subject. Check the minimum focusing distance of your lens.
    Minimum focusing distance for this lens is 20 inches.

  9. #9

    Default Re: Out of focus image

    hi all, thanks for your time in helping me out. Based on the consolidated comments from Sam, Zera and Flip, these are the summaries and my inputs:

    1) Camera backcapturing the more contrasty background thus throwing off the focus for the cat
    OWL: I indeed cropped off some of the image when posting up the cat into my multiply site. I am very sure that focusing was done on the cat's nose but it turns out it seems to be backcapturing the background. BUT at a f8 setting at maximum 135mm zoom, shouldn't I have enough DoF to cover the cat and the background? (I do have another cat image at the link below. This black and white cat looks sharper....... Think its the fur of the cat that is causing the issue? )

    2) Max zoom at 135mm resulting in wobbly hands...blurr image
    OWL: It was a pretty sunny day and I did have my Image stabiliser switched on. Will shaky hands be possible at those setting although its true I am already pushing my 28-135mm lens to its limits.

    3) Camera was too close to subject
    OWL: I am very sure I was at least 3 to 4 metres away from the kitty when I zoom my lens to maximum. Thus, I should say my 28 - 135mm should be focusing within its limits.

    4) Lens needs recalibration
    OWL: hahaha hopefully this is not the case. I've tried taking photographs around my neighbourhood and it seem that some of the images are still considerably sharp enough for me. How will you guys comment on the sharpness of the 2 images below?

    http://jksim.multiply.com/photos/hi-...hoto%2F11%2F15

    http://jksim.multiply.com/photos/hi-...photo%2F11%2F3

    (the 2 images above are not cropped)

    Keep the comments coming!!

  10. #10
    Moderator catchlights's Avatar
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    Default Re: Out of focus image

    the best way to confirm your lens has back or front focusing problem is to do a test.

    hope this help.
    Shoot to Live, Live to Shoot
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  11. #11
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    Default Re: Out of focus image

    It seems like a AF problem as I can see that high contrast objects are always in focus in ur pics...Have u tried manual focus and see how is it?

  12. #12
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    Default Re: Out of focus image

    It seems like a AF problem as I can see that high contrast objects are always in focus in ur pics...Have u tried manual focus and see how is it?

  13. #13

    Default Re: Out of focus image

    Personally felt is a random error. At times the focus can go off abit here and there. That may just be the shot that goes off lol. Anyway its not due to camera shake. 1/500 is way too fast and with IS the chance of camera shake induce blur is very low. Also your background was sharp so the only possibility is still the focusing.

  14. #14

    Default Re: Out of focus image

    I've some experince in shooting cats. One difficulty you may face is that the target is too furry and the camera will have problem determining the 'Correct' focus. If you aim the eye of the cat chances you wont miss. and 1/3 infront will be in focus this will mean the nose.

  15. #15

    Default Re: Out of focus image

    actually when shooting people or animals for that matter, using a pre selected af point would be more ideal than using the auto af.

    i'm assuming you were using auto af selection.

  16. #16
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    Default Re: Out of focus image

    If, it is really back focus problem of lens, i must say that is a pretty serious backfocus... looking from the image it seems to be off by probably 10"
    most backfocus problem lens only focus probably 1-2" off.

    so imho, it could be either user focus problem or AF point selection problem by either user or camera, both seems more likely than backfocusing problem cause by lens
    Last edited by ExplorerZ; 10th January 2008 at 12:46 PM.

  17. #17

    Default Re: Out of focus image

    Thanks for all the feedback. Flipfreak, when you mention using a "pre selected af point", do you mean setting only 1 of the red square in the view finder rather then letting the camera do a auto focus on multiple points?

    I'm trying to do a manual focusing but is very afraid that focus cannot be achieved coz the viewfinder is only this big and I can't really seem to be very certain that it is sharp enough.

    Anyone shooting images using full manual focusing? maybe can share your techniques in getting the sharpest focus?

  18. #18

    Default Re: Out of focus image

    Yes, select you AF point, dun let the cam do it.
    Did you use AF-S or AF-C?

  19. #19

    Default Re: Out of focus image

    do a lens test as catchlights suggested...

  20. #20

    Default Re: Out of focus image

    Hi,
    I am a newbie who has just bought a Nikon D40 DSLR. I went to the Expo CATS Car-Nival last Sunday to take some photos with my D40 and found that there are some pictures that are out of focus. An example is


    The settings i used were:
    Manual Mode
    ISO: 400
    Shutter Speed: 1/60 sec
    Aperture: f/6.3
    Flash: SB-600

    What could be the reason for the out of focus? Could it be because of
    1) Too close to the subject
    2) Wrong AF Point (I didn't realise that there are 3 AF points in D40 and I can actually select which AF point to use until I had this problem. Therefore I let the camera decide which AF point to use when I was shooting this picture. I will never do that again)
    3) My lens is backfocusing and I need to sent it to Nikon Workshop for repair.

    Hope that someone can help me find the root of the problem so that I would not make the same mistake again. Thanks
    Last edited by Weili80; 16th July 2008 at 12:41 AM.

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