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RS-1 Is this the wrong way round, if so...

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  • RS-1 Is this the wrong way round, if so...

    Hello guys,
    I am trying to figure out how to position the lens ring in the bracket.
    If it is put the way it is in the photo, the small stop pin on the bracket will stop the camera sliding forward, but then it hits a SPRUNG bar (lighter grey in the photo).
    As you can see, the lens ring is nowhere near the middle of the bracket.

    If I slide the lens ring into the bracket 180 from the way it is now, then the lens ring slides right into the bracket, but then there is nothing stopping it at the exact right spot. I can just centre it in the bracket, make sure it is as centred as possible, but I don't know that this is correct... seems like a stop of sorts makes sense, which is why I have it as I have it in the photo.

    Your help greatly appreciated.

    Samyang 7.5mm Non Olympus on a Panasonic GH4

    Thanks,
    Mark.
    This looks odd, lens ring is not in the middle of the bracket...

  • #2
    you can reverse the rotator by 180 degree. You can also remove the protruded “reading tab" on the QR clamp.
    A stop for this combo may not be possible.
    Last edited by nick fan; 10-29-2016, 12:58 AM.
    Fanotec
    We listen. We try harder.

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    • #3
      Hello Nick,
      So are you saying that the lens ring clamp should be in the centre of the bracket clamp for other to be positioned correctly ?

      I'm not sure which bit you mean I should remove... on the lens ring or the bracket ?
      And how do I calibrate it?
      There were no instructions at all with the NN device, I don't know what the QR clamp is.

      Thanks , Mark
      Last edited by markpalmos; 10-29-2016, 04:01 AM.

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      • #4
        Click image for larger version

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        The part circled in red can be removed if you don't want to mount the lens ring in other way (rotated by 180 degree).
        You can follow this tutorial for the NPP.
        http://johnhpanos.com/epcalib.htm
        Fanotec
        We listen. We try harder.

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        • #5
          Thanks Nick,
          I did manage to do a pretty good calibration
          SEE THIS PANO HERE https://goo.gl/photos/LBbCH9XGLHFmoxsr9
          But the problem I am having is getting the stitching errors to go away completely. This example has stitching errors in the ceiling edge above the stairs, and also in the wooden floor in the passage near the camera.

          I read that fish eye lenses do not have a constant NPP, ie you may be calibrated for the centre of the lens but not for the top and bottom edges. So is one to just be happy with this (not too bad) stitching as in my example above?

          Tx
          Mark.

          Originally posted by nick fan View Post
          You can follow this tutorial for the NPP.
          http://johnhpanos.com/epcalib.htm

          Comment


          • #6
            What stitcher are you using? If you are using PTGUI or Hugin, you can improve stitching by manually optimizing the lens parameter for the first time. Add more control points manually near the edges of photos. Optimize and Save the lens parameter for future use.
            The wall and ceiling lacks feature for auto control point generation. If you add a few control points manually at the corners, the error can be removed.


            Nick
            Fanotec
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            • #7
              BTW, anything you need to setup to display the spherical pano is google photos?
              Fanotec
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              • #8
                Mark, From the appearance of the nadir, it looks like the lower rail setting isn't optimum. See the tutorial referenced in the earlier post.

                John

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                • #9
                  Hi Nick and John.

                  Originally posted by nick fan View Post
                  What stitcher are you using? If you are using PTGUI or Hugin, you can improve stitching by manually optimizing the lens parameter for the first time. Add more control points manually near the edges of photos. Optimize and Save the lens parameter for future use.
                  The wall and ceiling lacks feature for auto control point generation. If you add a few control points manually at the corners, the error can be removed.
                  PTGUI. I enter 7.5mm for the lens, but change nothing else. What else is there to "optimise"? Should I do a shot in a church which has details 360x180 to create points, then save that as my template and apply that each time?

                  Originally posted by John Houghton View Post
                  Mark, From the appearance of the nadir, it looks like the lower rail setting isn't optimum. See the tutorial referenced in the earlier post.
                  Hi John,

                  I have noticed that the horizontal 6 images have no parallax problem but when I compare the horizontal shots with the shot where I tilt straight up at the ceiling, there ARE parallax problems. I don't know what that reveals, I have re-tested the horizontal bar distance, so perhaps it is the lens ring bracket... or just 7.5mm samyang anomaly?

                  WRT calibrating. I did this: tilting the camera directly down, take a shot, zoom in with the camera playback, and I did this repeatedly while adjusting the lower bar so that the the spirit level in the centre of the RD5 rotator is in the centre of the shot.

                  For the other adjustment, where the lens ring connects to the vertical bar, I used the matching a pin against the background to bring the camera forwards/backwards until panning the camera from side to side made no difference to the position of the pin compared to the distant background. (BTW, I feel that with this method, it seems the adjustment on the NN gear is much too crude. I was adjusting fractions of a mm to get this right... and this is a problem because on location, if I am to shoot the nadir hand held, I will have to remove the camera and lens ring each time, positioning it (accurately?) again each time.)

                  Thanks guys.
                  Mark.

                  Nick PS, not sure what you mean about the Google Photos... it displays rectilinear photos by default...
                  Last edited by markpalmos; 10-31-2016, 08:33 AM. Reason: did further test

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                  • #10
                    Mark,
                    When you click the "Advanced" tab in ptgui, you can see the lens parameters. You can save them as a preset or save the project as a template. This will reuse the lens parameters in new panos. So add more control points to the corners of the images and optimize the lens parameters for the first time.
                    The link you shared shows the equirectilinear image which is opened in a spherical view when I click on it. :-)
                    Fanotec
                    We listen. We try harder.

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                    • #11
                      Mark, With the camera pointing down, centering the bubble level in the image frame does not necessarily give you the correct lower rail setting. It may be good enough and is certainly a useful method in the field. Try taking two shots down with the head panned round 180 degrees between them. In PTGui, optimize with control points only on the floor and check that the centre of the rotator is properly aligned. The attached image shows the sort of view I mean, which is a psd layered file output displayed in Photoshop with the top layer at 50%.

                      As for the stitching errors occurring when the zenith shot is included, have you checked that the zenith image is in the correct orientation? It might be upside down if you have the auto rotate feature active in the camera. All the images need to be rotated from the camera's natural landscape orientation by the same angle - eg all rotated by +90 or all rotated by -90. Having a mixture will give problems owing to the way correction for an offset lens axis is applied via the lens shift parameters in the optimization.

                      If you care to make a set of jpeg images available, I would be happy to try and identify the cause of any stitching problems.

                      John

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                      • #12
                        Hi Nick and John, thanks both again for your responses.

                        John, that is a very kind offer, and I see what you mean by the bubble being "off"... which I will be able to test this on Wednesday, as I have other work stuff to attend to till then... in the meantime, I would greatly appreciate your input, if there is anything you can tell from my JPEGs... I have uploaded a zip containing 6 across two up and two down (it is about 65mb)
                        https://drive.google.com/file/d/0B9W...ew?usp=sharing
                        I had no idea a shot taken vertically could have an upside-down and have no idea how I would tell...

                        Originally posted by John Houghton View Post
                        Mark, With the camera pointing down, centering the bubble level in the image frame does not necessarily give you the correct lower rail setting.....
                        As for the stitching errors occurring when the zenith shot is included, have you checked that the zenith image is in the correct orientation? It might be upside down.....
                        If you care to make a set of jpeg images available, I would be happy to try and identify the cause of any stitching problems.
                        Nick,
                        Thanks, I think I need to invest more time in learning PTGUI. I see the advanced settings, but what I understand from what you are saying is I should create lots of control points in a shot, then optimise that, then save that as a template... Is that right?

                        Originally posted by nick fan View Post
                        Mark,
                        When you click the "Advanced" tab in ptgui, you can see the lens parameters. You can save them as a preset or save the project as a template. This will reuse the lens parameters in new panos. So add more control points to the corners of the images and optimize the lens parameters for the first time.
                        Thanks guys!
                        Mark.

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                        • #13
                          Mark, Your nadir and zenith shots are in landscape orientation, whereas the horizontal row shots are in portrait orientation. They need to be all in the same orientation (as I said). Rotate the nadir and zenith images clockwise by 90 degrees in Photoshop. (I used Irfanview to do a lossless rotation of the jpeg files). Having done that, you should get a better stitch. My project file is at https://www.sendspace.com/file/4ggvg9 . (It assumes the images have been rotated). I have included a note about PTGui and upside down images. Do read all of it. I would prefer all the shots to be given the same exposure, white balance and ISO to ease the blending task.

                          John

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                          • #14
                            Hi Mark,

                            A template with optimized lens parameter will save you lots of time in future stitching, especially in scene with little feature for automatic alignment.

                            Nick
                            Fanotec
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                            • #15
                              Thanks guys, stars, you both. . . I did the rotate trick, all shots vertical, and what do you know, an almost perfect stitch... I have no idea why that happens, as the matched points are still the matched points, regardless... but it does!

                              John, what about correct position on the horizontal bar? I see in the stitched photo HERE
                              https://goo.gl/photos/XA4x8HTswZaRvPEG9
                              the bubble is in very different positions when I rotate the NN by 90

                              How do I correct this (though if the bubble on the NN bracket is NOT centred, then...?)

                              Thanks again
                              Mark.
                              PS... no idea why exposure and ISO was not fixed, I had set a preset on my camera for shooting fully manually...
                              Last edited by markpalmos; 11-01-2016, 03:47 AM.

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