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Thread: problems by using the nadir adapter

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burake

Posts: 336
Location: Antalya, Turkey
Registered: 7 Jun 2012
problems by using the nadir adapter
Posted: 8 Oct 2012 at 20:58 GMT
updated: 8 Oct 2012 at 21:03 GMT
Hi everybody,
I finally got my nadir adapter and started using it...I followed this very comprehensive thread:
www.nodalninja.com/forum/showthread.php?3994-Nadi...
Now when I start to begin I do things correct I still have a big problem...I shoot on NN5 with a Canon 5DM2 and Canon EF 8-15 at 12 mm and stitch in PTGUI pro...4 shots around, 1 nadir shot and one patch shot...First I put my 4 images around (Nr.0,1,2,3) in PTGUI, crop and align...I run the optimizer, delete worst control points if possible and optimize again...Then I add the nadir shot Nr.4 (the shot where we can see the tripod completely) using viewpoint correction...In this shot I mask the tripod and also everything except the flat surface...I optimize, delete worst CPs of only 0,1,2,3, optimize again, delete worst CPs of all the images, optimize...Until here everything is fine...I add the patch image...Before I do anything I mask the tripod and everything except the flat ground...I add image 5 (this shot is not taken above the coin which I use as a marker on the ground but a little further to avoid a hole in my hardware combination) also using viewpoint correction...And when I optimize I get bad results...In the project below the average CPD was 1,00 and the worst CPD 3,01 when images 0 to 4 were aligned...After adding the patch image the average CPD "jumps" over to 2,25 and worst CPD to 13,05...Deleting worst CPs doesn't help, there are no statistical outliners...And when I check the CPs on the images they look quite well placed to me...This is my 5th try and it is always the same...The average CPD worsens strong after adding the patch image...What am I doing wrong?
Any help will be highly appreciated...
Here are the images and the PTGUI project file:
ge.tt/7lfye7P/v/0?c

Burak
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DennisS

Posts: 1787
Location: Los Anglels, United States
Registered: 1 Sep 2007
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 5:00 GMT
Burake,

You need to move the tripod over more when shooting the patch shot.

"Viewpoint Correction" was not turned on for the patch shot. Once you place a check mark in the box, leave it.

Do not use Viewpoint Correction for the Nadir shot. If your rig is calibrated correctly, your Nadir shot will be in the correct position along with all the other shots. Turning on Viewpoint Correction for the Nadir shot does not really get you anything.

The images are not lining up as well as they could. I think your pano head may not be completely dialed in yet.

Do not give too much importance on the final control point distance numbers. They are more of an indicator of what is going on, not the last word. Rely instead on how the final stitch looks. I have had panoramas with a maximum distance of around 5 stitch just fine. If I went through and played the game of deleting control points just to get the final number down, I could get the number under 2 without any improvement in the stitch. Let your eyes tell you when the stitch is done, not just the numbers.

Dennis
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Smooth

Posts: 4310
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 6:07 GMT
Burak,

My observations from your project file:

1. Crop Circle not set to optimal
2. Masking not complete
3. Spread of control points
4. No use of View Point Correction on image 5 (offset nadir)
5. Missing Vertical Control Points.

How to fix:

1. Set crop circle in the centre and adjust until you just capture/encompass the vignetting.
2. Not only mask the floor area, but all the image that is not flat floor and should be excluded.
3. Add more control points using Keyboard Shift key down, left mouse drag, draw rectangle, then right click "add control points here" remove bad control points in the usual way.
4. Check the VPC checkbox in the Optimizer for image 5.
5. Assign T1 Vertical control point and use the Panorama Editor to "Level Panorama" Keyboard Ctrl+Shift+V

Tips:

Control point placement on the VPC nadir image really only requires 3 control points per image. Try to place them in a triangular position.

I don't believe you need to shoot a nadir shot of the tripod/panohead. Some will argue for it but I have never seen the point. Give your Offset nadir image a little more tilt, to capture and cover the tripod and shadow area. You can check this for yourself by going to the "Create Panorama (Tab)" in PTGui and unchecking box 4 (image4) in the lower left and then opening the Panorama Editor to see this image isn't needed.

Download my version of the .pts file here www.omnipix.net/temp/smooth4burake.zip
Add it to the directory of your images and open to compare.

Regards, Smooth cool
www.omnipix.com.au
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John Houghton

Posts: 3934
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 8:11 GMT
One further observation: the viewpoint nadir image is upside down - i.e. it's in a different orientation to the other images. There are two indications of this: the crop circle is positioned differently and the vertical rail should appear on the same side in both nadir shots. Either the auto rotation feature is enabled in the camera or one image has been rotated by 180 degrees in Photoshop for some reason. This won't have any appreciable effect on the stitching here, but generally you should ensure that all images are in the same orientation.

John
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hindenhaag

Posts: 901
Location: Netherlands
Registered: 7 Mar 2010
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 11:47 GMT
Burak,

Besides all things already mentioned, it seems to me that your center column is a bit too long. It stands out below the corner of the nadir adapter and might cause a black area between the tip of the leg and the corner of the nadir adapter. Either you move aside a little bit more, > DPD, or you may use a shorter center column.

Heinz
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hindenhaag

Posts: 901
Location: Netherlands
Registered: 7 Mar 2010
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 17:45 GMT
@ Smooth,

Hi, I can not open your file but I am redirected to some rare pages. "File not be be found"

Regards,

Heinz
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Smooth

Posts: 4310
Location: Mount Panorama, Australia
Registered: 21 Jul 2004
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 17:51 GMT
Thanks Heinz I have corrected the link. Please try again.

Regards, Smooth cool
www.omnipix.com.au
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hindenhaag

Posts: 901
Location: Netherlands
Registered: 7 Mar 2010
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 18:11 GMT
Thx Smooth,

now it works.

"So long", cause it is always worth to follow your hints.

Heinz
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burake

Posts: 336
Location: Antalya, Turkey
Registered: 7 Jun 2012
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 21:39 GMT
updated: 9 Oct 2012 at 21:42 GMT
Dennis; thank you very much...Oh, yes...It's been some time since I have read about the viewpoint correction and of course there is this checkbox about the VPC next to the images smile...And you say it: it is the stitched image and not only the CPD numbers...Thank you very much for taking time...

Smooth; it was a pleasure to read your answer...Tons of useful information...I appreciate it highly...And thanks for taking extra time and preparing a project file...

John; thank you very much for your contribution, too...Autorotation is turned off...I shoot in RAW and when I open the images in ACR all the images are in horizontal position (landscape orientation)...This makes it difficult to set CPs by hand so I rotate them all 90 degrees clockwise...With the exception of the last image which I rotate 90 degrees counter clockwise..On this way when I have them in PTGUI next to eachother it is easier recognizing similarities and setting CP pairs by hand for images nr.4 and nr.5...Besides I just thought, when I would rotate the last image also in the same direction as the others the masked tripod parts would overlap and I would have a hole...

Heinz, thank you very much...You're right about the center column...With shorter center columns I got better results...In this shot I just forgot to make it shorter, it was still adjusted to my previous shooting without the nadir adapter...

Have a good evening all

Burak
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John Houghton

Posts: 3934
Location: Hitchin, United Kingdom
Registered: 17 Jan 2005
Re: problems by using the nadir adapter
Posted: 9 Oct 2012 at 22:42 GMT

burake said:

... I rotate them all 90 degrees clockwise...With the exception of the last image which I rotate 90 degrees counter clockwise..On this way when I have them in PTGUI next to eachother it is easier recognizing similarities and setting CP pairs by hand for images nr.4 and nr.5...

Burak, You can rotate the two images on the control points tab independently to facilitate manual control point placement. The reason why you should rotate all the images similarly in ACR is to enable the horizontal and vertical shift parameters to be shared by all the images for convenience in the optimization. If an image is upside down, the shift parameters will be applied in the opposite direction to that required to compensate for a lens axis offset from the centre of the sensor.

John
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burake

Posts: 336
Location: Antalya, Turkey
Registered: 7 Jun 2012
Re: problems by using the nadir adapter
Posted: 11 Oct 2012 at 7:51 GMT
John, thank you very much...
Burak
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