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Lightroom Profile to defish the Olympus 8mm f/1.8

Discussion in 'Olympus Cameras' started by azjsb, Mar 4, 2016.

  1. azjsb

    azjsb Mu-43 Regular

    95
    Sep 19, 2015
    I have been trying the various lens profiles in Lightroom to see which would do the best job to defish the Oly 8mm f/1.8 I just purchased. To me it looks like the Samyang 8mm f/2.8 UMC fisheye profile. The Bower and the Rokinon are close but, interestingly, not identical despite the fact that, I thought, all three brands come out of the same factory.

    Wondering what profiles you like and why. Don't want to go to all the manual machinations to defish - looking for a simple, one-click solution that is pretty (or maybe very) good.

    Thanks.
     
  2. bigboysdad

    bigboysdad Mu-43 All-Pro

    Aug 25, 2013
    Sydney/ London
    The Nikon 10.5mm fisheye profile works fine for me.
     
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  3. leungw

    leungw Deal Hunter

    339
    May 26, 2011
    NJ
    Willy
    Thank you for this. I just tried it and it does work reasonably well.
     
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  4. tradesmith45

    tradesmith45 Mu-43 All-Pro

    Dec 13, 2012
    Oregon
    How about using OV3? Doesn't it have a defish setting?

    Also take a look over at Lonley Speck.com. He has a de fishing method that leaves most of the AOV intac. I'll be trying bot approaches soon to see which I like best.
     
  5. leungw

    leungw Deal Hunter

    339
    May 26, 2011
    NJ
    Willy
    I have tried both OV3 and fisheye hemi. While they are both good, it's an extra step outside of Lightroom.


    Sent from my iPhone using Mu-43 mobile app
     
  6. azjsb

    azjsb Mu-43 Regular

    95
    Sep 19, 2015
    I want to thank Bruce McL - his post at Showcase - Panasonic 8mm f/3.5 provides a downloadable zip fle with the profile that he describes. Looks really very very good. Playing with the distortion slider a bit and is mid-90's tastes pretty darn good. Certainly adding it to my arsenal and it may very well become my "go-to" defish. Thanks, Bruce
     
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  7. MichaelSewell

    MichaelSewell Mu-43 Top Veteran

    511
    Sep 1, 2015
    Burnley, UK
    Michael A. Sewell
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  8. wjiang

    wjiang Mu-43 Hall of Famer

  9. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    The Sigma 10mm f/2.8 fisheye profile does a reasonable job. It's not perfect but it has a Distortion slider which runs from 0 to 200 with 100 being the default. I sometimes have to run it to 200 to get straight lines which are close to the camera to look straight. It's the best profile I've come across so far and it can turn this:

    _B160214.

    into this:

    _B160214-2.

    I pushed the Distortion slider to 200 in order to straighten that seam line in the concrete in the foreground.

    I tried the Hugin app that wjiang recommended but had difficulty working out what all of the options did and they didn't seem to have a document which explained the settings satisfactorily for me.
     
  10. MichaelSewell

    MichaelSewell Mu-43 Top Veteran

    511
    Sep 1, 2015
    Burnley, UK
    Michael A. Sewell
    Well, Plugins and automation have their place, but can occasionally let you down. Gaining the knowledge to manage the task manually, as you have demonstrated, is a skill worth having.
     
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  11. Bruce McL

    Bruce McL Mu-43 Veteran

    My Lightroom lens profiles for Olympus 9mm BCL:

    Olympus 9mm BCL tools.zip

    My Lightroom lens profiles for Panasonic 8mm ƒ3.5:

    Panasonic 8mm Profiles.zip

    Either one of these profile sets should work well with the Olympus 8mm ƒ1.8. I’d try the Panasonic 8mm profiles first.

    Where to put the lens profiles…

    on the Mac:

    Mac HD/Users/[username]/Library/Application Support/Adobe/CameraRaw/LensProfiles/

    on Windows, people suggest this:

    C:\Users\%USERNAME%\AppData\Roaming\Adobe\CameraRaw\LensProfiles
     
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  12. leungw

    leungw Deal Hunter

    339
    May 26, 2011
    NJ
    Willy
    It worked. Thank you! (For Windows, the MACOSX folder is not needed.)
     
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  13. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    I just tried your Panasonic profiles and they work very well. With the distortion slider at the default of 100, the result seems slightly better than the Sigma profile in that the extreme left and right edges don't look quite so stretched.

    Thanks for making these profiles available.
     
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  14. Bruce McL

    Bruce McL Mu-43 Veteran

    You are welcome folks. Glad I could help out. Keep taking pictures! :)

    I'll throw in one thing I've learned about using this kind of a lens: the "Fisheye rule of halves." The horizontal and vertical centerlines of the image are very important with fisheye. It's good to be aware of them when you compose. Putting your subject on one of these lines is a good place to start.
     
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  15. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    The thing to remember is the "Fisheye rule of diameters". Diameters are straight lines passing through the centre of a circle and the fisheye distortion is a circular distortion. Diameters are the only straight lines which a fisheye lens will not distort. The 2 centrelines are only 2 of the possible diameters of the circle, there are other diameters at any angle you choose. Any straight line which passes through the centre of the frame will be rendered as a straight line. Test it. Go out and find a fence with obvious vertical lines and take 2 photos, one with one of those lines on the vertical centreline and another with it at an angle you choose. Watch what happens to that line as you rotate the camera so the line starts to incline one way or another at an increasing angle. The line stays straight.

    Any straight line passing through the centre of the frame will remain straight. Straight lines which are parallel to a straight line passing through the centre of the frame will develop a bend and the degree of bend depends on how far they are from the line passing through the centre, but the degree of bend is not affected by the angle at which you incline the camera, only by the distance of the line from the centre.

    Placing important parts of the subject on the horizontal or vertical centrelines is a good idea because whatever is exactly on those lines will not distort so if you place the line where a pair of doors meet on the centreline, for example, the line where the doors meet will be straight and vertical, but the outer edge of each door will bend around the centreline, and so will the top and bottom of the doors. Now angle the camera at some angle, doesn't matter whether it is a nice neat angle like 30 or 45 or 60 degrees, or if it's something random like 23 or 37 or 69 degrees or any other angle you like. Provided the centre line of the doors passes through the centre of the frame and you have the centre of the frame placed on exactly the same spot where the doors meet, the doors will be exactly the same in each photo unless you have changed the distance from camera to the doors. The doors will look exactly the same in both images, only angled, just as they look exactly the same only angled if you take the same shots with a non-fisheye lens and angle the camera.

    But we like things to have the right horizontal and vertical alignments because that's the way we normally see the world so Bruce's suggestion about using the horizontal and/or vertical centrelines is a very good one. Just remember that just as you can tilt the camera to one side for visual effect with a non-fisheye lens, you can do the same with a fisheye and all straight lines passing through the centre of the frame will still remain straight.

    And now, for your next piece of fisheye homework, go and find a circular object such as a ceiling light fitting, stand directly under it and place the centre of the lamp directly on the centre of the frame, and take a photo. What shape does the circular object become? It stays circular. Points in the scene an equal distance from the focus point remain an equal distance from the centre of the image frame so circles photographed straight on remain circles if they are placed in the centre of the frame. Place them off centre and their shape changes.

    You can have a lot of fun learning how different sorts of lines and shapes will change depending on where you place them in the frame.

    After you've done that, try defishing the photos of the fence and of the circular object. You'll get a normal looking fence in both photos of the fence, with all of the vertical lines in the fence being straight, and the top and bottom of the fence being straight also provided they were straight, and your circular object will still be circular.

    Fisheyes can be a lot of fun.
     
    Last edited: Mar 6, 2016
  16. Bruce McL

    Bruce McL Mu-43 Veteran

    That's very good information about diagonals David, thanks for following up.

    Another advantage of using horizontal and vertical is that Lightroom allows you to adjust those two lines. That can be a big help.

    controls.JPG

    Like this:

    P1010469a.JPG

    and defishing exaggerates the distortion as you move away from the center

    P1010469b.JPG

    I am really enjoying mine.
     
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  17. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    Actually, it isn't exaggerating the fisheye distortion.

    Photograph something like that with a rectilinear wide angle lens and you will see the same distortion. It's actually normal ultra wide perspective which tends to stretch things the further they get from the centre of the frame. If we had a really short focal length rectilinear wide angle, around 5 to 6 mm in focal length, and you shot the same scene with it, you would see the same effect on the 2 outer circular shapes. The widest native rectilinear lens we have is probably 12mm in focal length and you may see that kind of distortion with it but not to the same degree so you may not notice it if you aren't looking.

    Here's a circular light fitting shot with the 12-40 PRO at 12mm:

    _3070005.

    You have to look closely but the same distortion is present in the shape of the light. It would become more apparent with a shorter focal length. In the case of your shot it also becomes a little more apparent because the circular skylight is at the end of a cylindrical tube and the opening in the ceiling and the skylight are no longer centred on the 2 outside skylights because you're not directly under them, and the fact that the skylight and opening aren't centred as they are with the centre skylight gives an uneven border to the skylight. The off centring also truncates the radial lines in the skylight on the side closest to the centre of the frame. Both of those things make the change in shape more noticeable whereas I've got a featureless white light fitting on a white ceiling here so there's only the outside shape of the fitting to go on.

    Defishing removes the fisheye "distortion" but it also means that your resulting image will have the normal perspective distortion you get towards the edges of the frame with a rectilinear lens.

    That's a very nice shot, by the way. I wish I had a subject like that in my home. I can manage this, however:

    _3070004.

    There's a line between the tiles on the floor leading from the back of the chair in the foreground to the kitchen bench in the background that passes very close to the centre of the frame and is almost straight. The lines parallel to it on the left are receding more directly away from the camera position so they show the expected bend around the centre of the frame. The parallel lines on the right recede at a more diagonal angle and don't bend as much. The circle of the Dyson fan on the right takes on a slight elliptical shape. The uprights of the bookcase on the right don't extend to the top of the frame at the top, and to close to the centre of the frame at the bottom. They curve, but because of the keystoning effect caused by pointing the camera down and their convergence as a result, plus the fact that they don't extend for the full height of the wall, they don't look as curved as the edge if the door frame on the right, even though the line of the top shelf shows noticeable curvature. The table in the background develops a noticeable bend to it's top surface but the bend in the tubular backrest of the chair in the foreground, which is a semicircular bend after a short length of straight side on each side ends up not looking quite as curved as it actually is because it's a receding curve and close to the horizontal centreline. There's some interesting curves in the furniture, a lot of receding straight lines in the floor and walls, and the photo is taken with the camera at an angle to all surfaces rather than straight on to any surface, and different things happen in different places as a result.

    Now we defish it with your preset and what do we get:

    _3070004-2.

    Just what we'd expect from a wide angle shot at an angle to every plane with lots of keystoning distortion, and it's fascinating seeing how straight lines and curves alter in various parts of the frame. Sorry to inflict my interior decorating taste on everyone :)

    Really nice correction in that profile of yours.
     
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