Problems Calibrating Olympus E-510 W/ 14 - 50mm lense [Archive] - Nodal Ninja Forum

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rcmagraw
07-06-2011, 11:20 AM
Hi everyone,

I've been struggling with getting my camera to calibrate correctly with the Nodal Ninja 3. I'm currently shooting at 14mm. I've positioned the vertical arm so that the camera is positioned over the nodal point. I followed a long with a online video which I'm not sure is correct. I positioned the vertical arm so that the cameras was centered over the center of the tripod head (nodal point).

I've positioned the horizontal arm so that it aligns correctly with objects when I pan. When I tilt the camera the object appear elongated. Which leads me to believe that the vertical arm is not positioned correctly. I'm not sure where to go from here. Please share any information you may have in resolving this issue.

Thanks!

Ryan

Bill Bailey
07-06-2011, 12:49 PM
Hi everyone,
I've been struggling with getting my camera to calibrate correctly with the Nodal Ninja 3. I'm currently shooting at 14mm. I've positioned the vertical arm so that the camera is positioned over the nodal point. I followed a long with a online video which I'm not sure is correct. I positioned the vertical arm so that the cameras was centered over the center of the tripod head (nodal point).
I've positioned the horizontal arm so that it aligns correctly with objects when I pan. When I tilt the camera the object appear elongated. Which leads me to believe that the vertical arm is not positioned correctly. I'm not sure where to go from here. Please share any information you may have in resolving this issue.
Thanks! Ryan
Hi Ryan - are you able to show us an image of your setup so we can confirm it is positioned correctly on the NN3?
thx
Bill

John Houghton
07-06-2011, 12:56 PM
Ryan, Your setup of the NN3 may well be adequate. You might try shooting a panorama and seeing how it turns out. However, I'm not convinced that you understand what you are doing, so take a look at these tutorials as well:
.
http://www.johnhpanos.com/epcalib.htm
http://www.easypano.com/forum/displa...1&TopicID=4162 (http://www.easypano.com/forum/display_topic_threads.asp?ForumID=1&TopicID=4162)
.
John

rcmagraw
07-06-2011, 01:28 PM
Bill and John,

Thanks for the replies. I'll work on getting some screen shots later tonight.

Ryan

hindenhaag
07-06-2011, 10:25 PM
Hi Ryan,

For first calibration for LRS = Lower rail setting set your center focus ring looking through the viewfinder in the middle of the NN logo. Then follow up the tutorial of Smooth. Imagine a circle saw blade: when the tooth cuts to the right, move the camera to the right. The tooth cuts to the left, move the camera to the left.

Concerning URS = upper rails setting with John's Tutorial: turning clockwise and the reference point follows the movement, move camera forward on upper rail. Turning clockwise and the reference point moves against the movement, move backwards.

For both LRS and URS try to find a point in between: the right point is the point where a mm more to the left or the right the Right Setting or a mm forward or backwards of the Right Setting should show changing the tooth cut from left to right or the reference point to follow or move against cameras movement.

Start from the front of the lens for URS, mostly near the golden ring viewing through your viewfinder watching the reference point and move camera backwards. Move by 5 mm intervals till you find the reference points movement changing from "with to against". Once the reference point changed from "with to against camera movement" move forward one by one mm till you find the URS.

Once you got the tricks to do it, you will find your settings for any other camera lens combination very easy. Even if you get data for your combination, you should test it with your own equipment following the tutorials to compensate small differences to your own equipment.

Regards,
Heinz

rcmagraw
07-14-2011, 01:01 PM
I convinced the issue I'm having is barrel distortion. I was able to calibrate my camera at 35mm without any parallax. When trying to calibrate at 14mm I ran to some issues with parallax. Is there anyway to resolve barrel distortion with upgrading the lenses.

John Houghton
07-14-2011, 01:39 PM
When trying to calibrate at 14mm I ran to some issues with parallax.
I don't understand. What issues are you having with parallax? Barrel distortion ought to be correctable by the evaluation of suitable lens parameters during optimization.

John

rcmagraw
07-14-2011, 05:10 PM
Here is my issue. I have found the correct rail setting for calibrating my lens at 35mm. The problem arises when shooting at 14mm. Theoretically, the lower rail should be correctly positioned from calibrating at 35mm. When I go to calibrate the upper rail there is parallax for both pan and tilt. The parallax is expected in tilt but i would assume the pan would be correct. With that said, I go through the same process of calibrating the lower rail and upper and am unable to remove parallax which leads me to believe that it's barrel distortion.

DennisS
07-14-2011, 05:31 PM
Stop making assumptions. That is your main problem.

Barrel distortion is very large with a 8mm fisheye lens. Panoramas shot with this (and other) fisheye lenses stitch just fine. Do not focus on barrel distortion any more.

Do not assume what works for 35mm works at 14mm. Theoretically the lower rail setting should not change, but I would not assume anything. If your camera is mounted absolutely perfectly square and plumb, then the lower rail SHOULD not change.

You need to go through the entire calibration exercise with your lens set at 14mm.

hindenhaag
07-14-2011, 11:31 PM
Hi Ryan,

Just send the set of pics and we will try to fix your problem.

Regards,
Heinz

rcmagraw
07-16-2011, 03:36 PM
Here are some images. Please help

Lower Arm Settings:
http://imageshack.us/photo/my-images/97/lowerarm.jpg/

Image Overlay:
http://imageshack.us/photo/my-images/828/overlays.jpg/

Middle Image:
http://imageshack.us/photo/my-images/33/middleimage.jpg/

Pan Image:
http://imageshack.us/photo/my-images/28/panimage.jpg/

rcmagraw
07-18-2011, 05:23 PM
I posted a reply with some images but it looks like it didn't go though.

John Houghton
07-18-2011, 11:56 PM
Upload the images somewhere and just post a link to them here. You can use a free file hosting site such as http://www.zshare.net if you don't have your own personal web space. It's helpful if you parcel all the images together in a single zip or rar archive file using a utility such as 7-zip (for Windows).

rcmagraw
08-07-2011, 02:45 PM
Here you go. Sorry it took so long to respond.

Please help :)

shots.zip - 4.43MB (http://www.zshare.net/download/93435424c9c0c79b/)

John Houghton
08-07-2011, 11:41 PM
Thanks for the shots, but it's not obvious what they are intended to show. The "middle" and "pan" images seem to be absolutely identical.

John

hindenhaag
08-08-2011, 12:36 AM
John,

middle and pan are taken to check the movement of the reference point when turning to the right. Might be he should have moved a little bit further to the overlap area. The nails don't seem move in these example.

For LRS he has focused down to the logo. Would have been better if we could see the focus point from the camera.

RC, you get better results about a "moving reference point" when you check it to something which is far away, like a house etc.

Heinz

rcmagraw
08-08-2011, 01:14 AM
Sorry about that guys! Look like I someone how saved pan shot over the middle. I attached a new link with some quick pictures I took this late evening. I apologize for the composition it was the best I could do this late at night. But you should be able to see what's going on...

newshots.zip - 6.98MB (http://www.zshare.net/download/93447598e9b7b6f8/)

John, what do you mean by the focus point of the camera?

John Houghton
08-08-2011, 02:37 AM
The new pair of images are fine. What exactly is your main concern? There's a small amount of parallax shift visible, but probably not enough to prevent a good stitch from being obtained for typical panoramas. You should really be checking for parallax in the same conditions as for shooting a panorama - i.e at yaw positions -/+ half the normal yaw increment, e.g. -15 and +15.

In what context does "focus point of the camera" appear?

John

hindenhaag
08-08-2011, 03:08 AM
John,

I mentioned that I can see my "focus ring" while focussing to the logo for example.

He has problems with his setting.

Checking the two new pics, you can see that the top of the nail in front moves with the movement of the camera: in the first, the left side of the top ends in the middle of the wood on the right side. On the second, it has moved to the line in between the two boards. RC, this means your reference point moves with the movement of the camera and as consequence you have to move forward on the upper rail.



Regards,
Heinz

BTW: I have learned from John, that we always shoot the pano by moving to the right. This is the normal way to do it. This will keep your screws fixed, turning to the left may loosen your screws and the head will move.:wink::wink:

rcmagraw
08-08-2011, 03:45 AM
Issue 1: My main concern is that even though it appears my pan head is calibrated correctly I'm still seeing parallax in my panoramas. It's primarily in the set of images that are taken at a 45 tilt. From my understanding if pan is calibrated correctly so should tilt. If that's the case how would I adjust for tilt?

Issue 2: I'm currently shooting 12 images at 30 apart at varying angles of 90, 45, 0, -45 and -90. The issue I'm having is aligning the 90 straight up shot. PTGUI has issues plotting control points between the image 0 and 1. Mainly because there is not enough information to plot points between images. " this is not related to the parallax issue but I just thought I would bring it up"

Ryan

John Houghton
08-08-2011, 05:56 AM
I wonder how you "see parallax in your panoramas"? It would be a good idea to supply the 12 images at pitch 45 so that the real problem can be investigated. They need not be 2MB each if you choose a quality setting equivalent to 9 in Photoshop, at which they should be around 300KB. Irfanview will resave in batch mode quite simply.

If there's no detail for control points at the zenith, then you should be able to position the zenith image manually. You should know the nominal yaw, pitch and roll angles of all the images. If you enter these to initialize the project, the zenith will remain in position reasonably aligned without control points.

John

rcmagraw
08-08-2011, 12:04 PM
Here is a quick panorama I shot of my apartment. Let me know if you have any luck getting it to stitch correctly.

project.zip - 8.69MB (http://www.zshare.net/download/9346454451b2602e/)

Ryan

rcmagraw
08-08-2011, 12:11 PM
Looks like the camera data wasn't included in the jpeg's I batched. The focal length for the shots is 14mm with a focal length multiplier of 1.923.

Ryan

DennisS
08-08-2011, 01:37 PM
I had to key in the lens parameters, assign control points to tie in the zenith and do just a touch of masking between a couple of images (in order to move the seam into the shadows and such). Otherwise PTGui 9.1 beta 1 stitched this one just fine. I see no alignment or "parallax" issues.

John Houghton
08-08-2011, 02:19 PM
Ryan, I stitched it ok. No masking applied. I used temporary line control points (t3) to align the ceiling. I haven't done an intensive search for stitching errors, but it looks reasonable. I did make an adjustment to the white balance when I resized the output down. I put the project file and 5000x2500 stitch at:
http://www.johnhpanos.com/project2jh.zip
.
John

rcmagraw
08-08-2011, 02:56 PM
John,

Great Job! It looks great! I appreciate you taking the time to do that. How did you add the temporary line control points?

Ryan

John Houghton
08-08-2011, 10:56 PM
t3,t4,t5 ... tn points can be assigned along line features that cross from one image to another such as the beam across the ceiling in your images. The PanoTools optimizer (not PTGui's normal optimizer) will then try to get all those points in straight lines across the output area and thus align those features. However, in the equirectangular projection, those features should be curved, not straight, so it's not apprpriate to use that technique without some trickery.
.
The trick is to shift the zenith down to the middle of the output area and then switch to rectilinear projection. The horizontal and vertical fov needs to be reduced to 120, say. Then, the line features in the ceiling will be straight and the optimizer has a sporting chance of getting the rows of tn points aligned.
.
So, after the alignment of the zenith image has been successfully performed by PTOptimizer, the panorama projection can be switched back to equirectangular and the zenith shifted back to its usual position. The tn points are no longer needed and can be deleted. The panorama can be levelled with t1 points using the normal optimizer or the levelling option on the Panorama Editor window without disturbing the alignment of the images.
.
John

rcmagraw
08-09-2011, 11:59 AM
I did not see any t3, t4 or t5 control points used in the project file. I did however, see that you used a couple of t1 control points to adjust the vertical alignment in the panorama. Which proved to be very useful when aligning the ceiling. I used the project file you provide me as a learning guide to see where I went wrong. My biggest problem was that I wasn't using any of PTgui plugins. Having the right optimizer plugin with the correct settings, fixed a lot of issues.

Thanks again for all of the help!

Ryan Magraw

John Houghton
08-09-2011, 12:56 PM
Ryan, there were no tn points in my project file as they were temporary. Once the equirectangular image was resored to its normal orientation, they were not needed and I then added the t1 points to level the panorama. The fairly new version of PTOptimizer available from the PTGui web site is useful occasionally, but for the most part, PTGui's own optimizer is all that's needed.

John