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Thread: Angular Distortion in WA lenses

  1. #1
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    Default Angular Distortion in WA lenses

    I am using a Tokina 12-24 DX lens.

    When I am talking about angular distortion, I mean that rectangles become parallelograms, especially at the corners.

    Looking at some buildings at the corner at the 12mm setting would give you rectangles transformed into a parallelogram with quite an acute angle.

    Wonder if shooting at 18mm in FF would give the same angle of view, but would the angular distortion be somewhat less. I suspect that it would be less in the case of FF. Can anyone confirm that.

    [hope that my lingo is clear enough here for most readers to understand]
    Do not be afraid [of ghost and bullies] Shoot them......

  2. #2

    Default Re: Angular Distortion in WA lenses

    You mean perspective distorting when you tilt your camera up/down with wide angle lenses? It related to your distance to subject.
    Last edited by J-Chan; 20th March 2012 at 10:19 PM.

  3. #3

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    Why do you think it would be less? Fyi, you could read reviews. They usually cover lens distortion as well.
    Alpha

  4. #4

    Default Re: Angular Distortion in WA lenses

    Quote Originally Posted by La Fontaine View Post
    I am using a Tokina 12-24 DX lens.

    When I am talking about angular distortion, I mean that rectangles become parallelograms, especially at the corners.

    Looking at some buildings at the corner at the 12mm setting would give you rectangles transformed into a parallelogram with quite an acute angle.

    Wonder if shooting at 18mm in FF would give the same angle of view, but would the angular distortion be somewhat less. I suspect that it would be less in the case of FF. Can anyone confirm that.

    [hope that my lingo is clear enough here for most readers to understand]
    Maybe you should invest in a tilt and shift lens if you like photographing interiors or buildings.

    View Camera Movements: Why Tilt and Shift?

    Using Tilt-Shift Lenses to Control Perspective

    Focusing Tilt Shift Lenses

    What is Tilt-Shift? (Feat. Canon TSE 17mm f/4) - YouTube
    Last edited by one eye jack; 21st March 2012 at 04:24 PM. Reason: url mistake

  5. #5
    Senior Member digitalpimp's Avatar
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    Default

    Distortion is an inherent characteristic of an UWA lens. You really have to be mindful of your angles to minimise it.

    edutilos- did a nice tutorial on distortion correction. It's buried deep in the CS database so you have some serious digging up to do (unless he sees this and provides us with the link).

    Also, you can try reading up on PTLens. It's a plugin that can help you correct distortions with just a few clicks. I use it personally. Just make sure it has the proper profile for your lens.
    Last edited by digitalpimp; 22nd March 2012 at 03:22 AM.

  6. #6
    Senior Member Kit's Avatar
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    Default Re: Angular Distortion in WA lenses

    Quote Originally Posted by La Fontaine View Post
    I am using a Tokina 12-24 DX lens.

    When I am talking about angular distortion, I mean that rectangles become parallelograms, especially at the corners.

    Looking at some buildings at the corner at the 12mm setting would give you rectangles transformed into a parallelogram with quite an acute angle.

    Wonder if shooting at 18mm in FF would give the same angle of view, but would the angular distortion be somewhat less. I suspect that it would be less in the case of FF. Can anyone confirm that.

    [hope that my lingo is clear enough here for most readers to understand]
    We first have to identify what kind of distortion you are referring to. A photo will be great.

    There are general 3 kinds of distortions associated with UWAs, perspective distortions, keystone effects and curvilinear distortions.



    academic facility - laboratory by arkitectural photography, on Flickr
    Taken with a 14-24mm at 14mm.

    From the way you've described, I'll hazard a guess and think that it was perspective distortions. This is inherent in UWA design and cannot be corrected. This is the best example I can find in the office. Take a look at the floor tiles at the bottom of the frame and the tables in the near distance. They are being skewed out of proportion and shape. That is perspective distortion associated with a UWA and they cannot be corrected. Their impact can however, be minimised with careful framing. Personal, I'd like to go wild on these because they can make a composition look more dynamic.

    About tilt/shift lenses.....
    They are used to correct keystone effects which are commonly seen in architectural photography where you need your vertical lines to be straight without cropping out bits or parts of your subjects.


    As you can see, the photo was corrected with with a tilt/shift lens. If you were to pay attention to the top of the building, geometric distortion is still pretty evident. the building is being skewed out of shape by the UWA tile/shift. That's inherent in the lens design.



    people's park complex by arkitectural photography, on Flickr
    Example of keystone effect, uncorrected.

  7. #7
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    Default Re: Angular Distortion in WA lenses

    Quote Originally Posted by Kit View Post
    We first have to identify what kind of distortion you are referring to. A photo will be great.

    There are general 3 kinds of distortions associated with UWAs, perspective distortions, keystone effects and curvilinear distortions.



    academic facility - laboratory by arkitectural photography, on Flickr
    Taken with a 14-24mm at 14mm.

    From the way you've described, I'll hazard a guess and think that it was perspective distortions. This is inherent in UWA design and cannot be corrected. This is the best example I can find in the office. Take a look at the floor tiles at the bottom of the frame and the tables in the near distance. They are being skewed out of proportion and shape. That is perspective distortion associated with a UWA and they cannot be corrected. Their impact can however, be minimised with careful framing. Personal, I'd like to go wild on these because they can make a composition look more dynamic.

    About tilt/shift lenses.....
    They are used to correct keystone effects which are commonly seen in architectural photography where you need your vertical lines to be straight without cropping out bits or parts of your subjects.


    As you can see, the photo was corrected with with a tilt/shift lens. If you were to pay attention to the top of the building, geometric distortion is still pretty evident. the building is being skewed out of shape by the UWA tile/shift. That's inherent in the lens design.



    people's park complex by arkitectural photography, on Flickr
    Example of keystone effect, uncorrected.
    Thanks bro Kit for the lesson in WA distortion.

    So, now I know it is called perspective distortion. In the laboratory picture, the floor tiles at the right side looks very much distorted, in terms of the angle. This is what I am referring to.
    Do not be afraid [of ghost and bullies] Shoot them......

  8. #8
    Senior Member Kit's Avatar
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    Default Re: Angular Distortion in WA lenses

    That is something which cannot be corrected. Comes with UWAs.

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