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  • Why?

    Can anyone explain, why my my 7-14mm luminous lens is 114 degree field of view at the wide end when the Yamsang fisheye 7.5mm is 180 degree field of view. I would have thought being a similar focal length would give much the same field, obviously there is a technical reason.
    I am considering buying one, reports say its a super sharp lens.
    Patrick

  • #2
    Re: Why?

    Yes, fisheye lenses are not rectilinear so the way the field of view is calculated in relation to the focal length is different. Rectilinear lenses are where the optical design aim is to maintain straight sides and the same perspective as a pin hole camera.

    Ian
    Founder/editor
    Four Thirds User (http://fourthirds-user.com)
    Digital Photography Now (http://dpnow.com)
    Olympus UK E-System User Group (http://e-group.uk.net)
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    • #3
      Re: Why?

      Thank you Ian

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      • #4
        Re: Why?

        If you use software to "de-fish" an image from a fisheye lens, you'll see that as the curved lines get unbent, a significant part of the frame gets lost--it gets cropped out of the edge to create a rectangular image. A rectilinear lens like the 7-14 essentially does the same thing using optics.

        - Hal -
        A Still Mind - Photography, Music, Meditation, Ministry - www.astillmind.net
        Olympus E-M5; Panasonic-Leica DG Summilux 25mm; Zuiko 12-60 SWD, 50-200 SWD; Sigma 105 Macro; Rokinon (Samyang) 7.5mm fisheye; Olympus 8/1.8 PRO fisheye; FL-50R; Giottos MT-8361 tripod with Gitzo GH2780QR ballhead.

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        • #5
          Re: Why?

          I thanks for your response, before posting I had an idea about this, Ian's reply sort of confirmed it. Your reply confirms it most clearly.

          Patrick

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          • #6
            Re: Why?

            You can't use a 7.5mm if you have big feet, they will appear in every shot.

            The 7-14 is really superb.

            Have fun.
            Graham

            Keep smiling, it gets folk wondering what you've been up to

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            • #7
              Re: Why?

              I,m size 101/2😉we shall see how I get on, I have just won a second hand example on eBay.
              I first got interested in fisheye photography when I had a fisheye add on lens for my iPhone, gave impressive results.

              I plan experimenting with panoramas with the lens, could be fun or great disappointment, we will see.

              Patrick

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              • #8
                Re: Why?

                They are a good "fun" lens that with the right subject can work really well.

                Please show us your results.
                Graham

                Keep smiling, it gets folk wondering what you've been up to

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                • #9
                  Re: Why?

                  I have the Samyang 7.5mm fisheye and love it--it's quite sharp and a lot of fun. I do have to be careful about how I hold the camera because it's easy to get my fingers in the corners of the pictures. And if you point the camera down just a bit, your feet will appear, especially in vertical images. The challenges of composition are just part of the fun.

                  - Hal -
                  A Still Mind - Photography, Music, Meditation, Ministry - www.astillmind.net
                  Olympus E-M5; Panasonic-Leica DG Summilux 25mm; Zuiko 12-60 SWD, 50-200 SWD; Sigma 105 Macro; Rokinon (Samyang) 7.5mm fisheye; Olympus 8/1.8 PRO fisheye; FL-50R; Giottos MT-8361 tripod with Gitzo GH2780QR ballhead.

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                  • #10
                    Re: Why?

                    Well the lens arrived yesterday, not been able to try it out yet but here is a shot taken in my room at home.
                    Not quite as sharp as I had hoped, the reviews say how sharp it is.

                    Hope to give it a proper tryout Sunday.

                    Patrick
                    Attached Files

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