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Thread: Help... Horrible lens distortion problem...

  1. #1
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    Default Help... Horrible lens distortion problem...



    I have this photo as shown above. The lens distortion is horrible... The Eiffel Tour is not vertical, but the horizon is horizontal. When I used Photoshop CS3 to correct this distortion, either the tower is vertical, but the rest of the image suffers horrible distortion (and the horizon is extremely curved), or as you have seen above, everything else is fine, but the tower is not 90 degrees to the ground... What should I do? Anything I can do within photoshop? Or do I need more sophisticated lens-distortion-software? Thanks a lot. I really want to save this image.

  2. #2

    Default Re: Help... Horrible lens distortion problem...

    the easiest way that comes to mind is to liquify the tower straight...

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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by theRBK View Post
    the easiest way that comes to mind is to liquify the tower straight...
    Can enlighten me on that? How do I proceed? In photoshop?

  4. #4

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by theRBK View Post
    the easiest way that comes to mind is to liquify the tower straight...
    Liquify? I think Free Transform would be easier, drag the bottom left edge towards the left, or the top left edge towards the right, would stretch the tower so it would look vertical
    Last edited by brapodam; 19th February 2011 at 08:16 PM.

  5. #5

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by FrozenRiver View Post
    Can enlighten me on that? How do I proceed? In photoshop?
    in Photoshop... it is under the "Filters" menu...
    Quote Originally Posted by brapodam View Post
    Liquify? I think Free Transform would be easier, drag the bottom left edge towards the left, or the top left edge towards the right, would stretch the tower so it would look vertical
    you tried that?... would it not cause the rest of the image to be crooked now?

  6. #6

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by theRBK View Post
    in Photoshop... it is under the "Filters" menu...you tried that?... would it not cause the rest of the image to be crooked now?
    If you drag it from the top left corner, the distortion to the surrounding buildings should not be very noticeable as they are very small in the photo.

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    Senior Member edutilos-'s Avatar
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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by FrozenRiver View Post
    Can enlighten me on that? How do I proceed? In photoshop?
    You have to experiment yourself, do note that liquify does degrade pixels, so do it in max resolution. I use liquify a lot of the time, in particular for seascapes, where to get the composition you want, you often have to tilt your lens downwards... Like you have done here for this shot.

    As a correction, this is not lens distortion, so don't blame it on the lens. I know the location you are shooting from, and you have to tilt the lens down to get this... If you have made it perfectly vertical, yes, there might be some distortion, but not to this extent. The term for this is "vertical perspective distortion" - which you can control. But as I said earlier, it is unavoidable sometimes (like in this case).




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    Senior Member edutilos-'s Avatar
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    Default Re: Help... Horrible lens distortion problem...

    Also, I can't really see the building details - I bet La Defense is also wonky, so my correction may not be perfect if it was applied to a huge picture.

    Liquify maximum brush size is quite small for CS2, I think 800 pixels? I have since upgraded to CS5 but haven't used anything in between, so no clue on what the max brush size is there.. But in CS5 it is 1500 pixels.

    If you find it hard to use a 800 pixel brush to modify a full resolution image (and you will), suggest you:
    IMAGE DUPLICATE
    --> RESIZE TO 800 PIXELS (or whatever is optimal to you)
    --> DO THE LIQUIFICATION
    --> SAVE MESH
    --> GO BACK TO ORIGINAL FULL RESOLUTION IMAGE
    --> LIQUIFY
    --> LOAD MESH FROM LOCATION SAVED IN.

    Will save you loads of grief. Hope this helped, though I suspect you will be in for a long, painful experimentation exercise. The first time I touched Liquify, I spent 3 or 4 hours playing with it to correct the image, gave up, and deleted it. These days, thankfully, that timing has been reduced to something like 15 minutes tops. So don't give up!

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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by edutilos- View Post
    Also, I can't really see the building details - I bet La Defense is also wonky, so my correction may not be perfect if it was applied to a huge picture.

    Liquify maximum brush size is quite small for CS2, I think 800 pixels? I have since upgraded to CS5 but haven't used anything in between, so no clue on what the max brush size is there.. But in CS5 it is 1500 pixels.

    If you find it hard to use a 800 pixel brush to modify a full resolution image (and you will), suggest you:
    IMAGE DUPLICATE
    --> RESIZE TO 800 PIXELS (or whatever is optimal to you)
    --> DO THE LIQUIFICATION
    --> SAVE MESH
    --> GO BACK TO ORIGINAL FULL RESOLUTION IMAGE
    --> LIQUIFY
    --> LOAD MESH FROM LOCATION SAVED IN.

    Will save you loads of grief. Hope this helped, though I suspect you will be in for a long, painful experimentation exercise. The first time I touched Liquify, I spent 3 or 4 hours playing with it to correct the image, gave up, and deleted it. These days, thankfully, that timing has been reduced to something like 15 minutes tops. So don't give up!
    Thank you. This picture was actually inspired by a few of yours taken at the same spot. I am sure you know which ones I was referring to. I didn't know Tour Montparnasse before I saw your pictures.

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    Senior Member edutilos-'s Avatar
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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by FrozenRiver View Post
    Thank you. This picture was actually inspired by a few of yours taken at the same spot. I am sure you know which ones I was referring to. I didn't know Tour Montparnasse before I saw your pictures.
    It 's a nice place - I've been there twice, I must say it's one of the few places in Paris I actually miss. Just being there, especially at sunset, was great.

    Sometimes, I don't understand why people want to go up the Eiffel, since when you're on it, you don't see anything iconic and unique to Paris... But we digress.

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    Default Re: Help... Horrible lens distortion problem...

    Liquidify can indeed do magic. Thanks you guys!

  12. #12

    Default Re: Help... Horrible lens distortion problem...

    I wANt to try this technique...

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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by niceboyatsg View Post
    I wANt to try this technique...
    Try it. It's really useful, plus it feels magical...

  14. #14

    Default Re: Help... Horrible lens distortion problem...

    Forget liquify. Use the Transform tool set to "perspective." Narrow the top of the image until the tower is plumb. Then crop.

    (Work with the original image rather than the cropped version that you posted.)

    Last edited by Peano; 20th February 2011 at 11:37 PM.

  15. #15

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by Peano View Post
    Forget liquify. Use the Transform tool set to "perspective." Narrow the top of the image until the tower is plumb. Then crop.

    (Work with the original image rather than the cropped version that you posted.)

    To each his own.. There are different ways to correct such distortion.

    Though we welcome inputs from fellow members, your comment on other's input was uncalled for.

  16. #16
    Senior Member edutilos-'s Avatar
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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by Peano View Post
    Forget liquify. Use the Transform tool set to "perspective." Narrow the top of the image until the tower is plumb. Then crop.

    (Work with the original image rather than the cropped version that you posted.)
    The reason why I choose to use liquify is to retain the original composition. I can't think of any other way to do so, though I think warp is possibly helpful here.

    Maybe you could take a look at your resultant image - where there was a inverse Y, (or gamma, if you will) now part of it is chopped off. The composition is a lot less effective than the original.

  17. #17

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by chiangkxv View Post
    your comment on other's input was uncalled for.
    I respectfully disagree. Here's the problem with using liquify. That filter will straighten only the tower. The lens distortion affects the entire image, not just the tower. To correct the distortion, it's necessary to transform the perspective of the whole image. Liquify won't do that. It's no insult to anyone to point out the limitations of that tool.

  18. #18
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    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by Peano View Post
    I respectfully disagree. Here's the problem with using liquify. That filter will straighten only the tower. The lens distortion affects the entire image, not just the tower. To correct the distortion, it's necessary to transform the perspective of the whole image. Liquify won't do that. It's no insult to anyone to point out the limitations of that tool.
    I agree with your statements in red.

    But here's something to highlight - does the rest of the image's distortion bother you?

  19. #19

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by edutilos- View Post
    does the rest of the image's distortion bother you?
    It isn't my image, so nothing about it bothers me. But if the OP wants to fix the lens distortion, it will be necessary to make a global transformation. Notice how the buildings are skewed all over the image.

    If it were my image, I would straighten those leaning buildings. Others might be happy to straighten only the tower and leave everything else distorted. I suppose it's a matter of personal preference.


  20. #20

    Default Re: Help... Horrible lens distortion problem...

    Quote Originally Posted by FrozenRiver View Post


    I have this photo as shown above. The lens distortion is horrible... The Eiffel Tour is not vertical, but the horizon is horizontal. When I used Photoshop CS3 to correct this distortion, either the tower is vertical, but the rest of the image suffers horrible distortion (and the horizon is extremely curved), or as you have seen above, everything else is fine, but the tower is not 90 degrees to the ground... What should I do? Anything I can do within photoshop? Or do I need more sophisticated lens-distortion-software? Thanks a lot. I really want to save this image.
    using PhotoFiltre (free photo editing software), adjust trapezoid/perspective, distort bottom by 130%, you will get;
    you can buy better gear but you can't buy a better eye

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