panorama software,virtual tour software
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Joined: 2005-12-18
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2006-01-06
#1

stitching error

hi

I've got this slight stitch error which i know is a slight misalignment. The kit is a D70 with Sigma 8mm. As the fault is much more pronounced on the top and bottom lines, can someone give me any pointers as to which way to adjust?  Its using an Agnos MrotatorT bracket and I've already lined up the horizontal adjustment to minimise the jutting effect on the base of the tripod. 

Also - would the camera have to be exactly horizontal as the bracket doesn't lock in very well occasionally and I wondered if it wasn't bang on whether that was causing some problems? A spirit level on the camera shows its pretty good...

Cheers

Andy

PS - Cheers to Smooth for giving me such good pointers last question - I'm a lot closer now, thank you!

 


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Joined: 2005-05-15
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2006-01-13
#2

Hi Friends,

I have the exact same problem described as above. The error only happens at the very bottom and at the very top.

I use a tripod leveler and a remote. Do you think this is a nodal point issue?

General Lee


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2006-01-13
#3

I too had some stitch errors that I can not post at this time to view for I am at work away from my computer.  However, 360 Dave and I talked about these issues on another thread.  He gave me an idea of using the matching points to see if it would correct.  I have not yet done this but will post results here when achieved.  Just thought I would share the idea.

Regards, Pixel


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2006-01-13
#4

I have tried matching points. I have tried setting 6 and 10 points.

I have also tried setting 6 points and then setting 6 different points on the same pano and still get the error.

Sometimes it is really bad. At other times it is not. I am just not sure what is causing this. Mabey my rotator needs maintenance, or mabey  my tripod is wearing out.

But sometning is causing these paralax errors.

General Lee


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2006-01-16
#5
hey guys... I think I'm having similar problem. I tried leveling my camera but I think its already correct.
So what could be the solution for my case?

http://img485.imageshack.us/img485/8073/problem9hb.jpg


The problem is not only at the bottom where one would say it can be easily photoshopped.
notice that it shows in the middle of the pano where the walls meet the ceiling.

I tried shooting 6 images and stitching them with the full frame option. the results were correct. But I still want to stitch 4 not six since I'm using sigma fisheye 8mm.
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2006-01-16
#6

With out seeing the affected images it is really hard to determine the issue.

First make sure you are stitching Drum or Full Frame (there is a personal joke here). 

I think the reason PW 4 has X and y dimension adjustments is because sometimes inside the camera the SENSOR is not perfectly aligned with the perpendicular lens axis.  Means the sensor is off center from the center of the lens.  Even different Canon 20d camera sensors can be off set by a few microns.

PW4 allows you to adjust the center of the sensor/ image with the lens as well as.. making cropping adjustments to remove the black background and light fall off purple fringe the at  the lens edge rim.  Thats where the glass meets the metal lens housing.

If Drum.. check the image "sensor" alignment X and Y and R for radius by trying to make it larger or smaller radius.

 


/s/
Dave
Forum Moderator for
EasyPano - Panoweaver
Pano2VR


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2006-01-16
#7
Quote: Originally posted by 360texas on January-16-2006

First make sure you are stitching Drum or Full Frame (there is a personal joke here). 

 


LOL  
The personal joke that Dave is refering to is that I was using Full Frame instead of Drum.  My set up is a Canon 350D, Sigma 8mm wich in fact produces drum.  I am still trying to tweak my image with what seems to be stiching errors though.  I believe at this point I am going to try and reshoot, after shooting the 4 stops and top image, remove camera from tri-pod and shoot bottom.  This was suggested as an idea, so to leave no stone unturned I am going to give it a try.

Regards, Pixel


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2006-01-16
#8
Quote: Originally posted by 360texas on January-16-2006

With out seeing the affected images it is really hard to determine the issue.

First make sure you are stitching Drum or Full Frame (there is a personal joke here).

I think the reason PW 4 has X and y dimension adjustments is because sometimes inside the camera the SENSOR is not perfectly aligned with the perpendicular lens axis. Means the sensor is off center from the center of the lens. Even different Canon 20d camera sensors can be off set by a few microns.

PW4 allows you to adjust the center of the sensor/ image with the lens as well as.. making cropping adjustments to remove the black background and light fall off purple fringe the at the lens edge rim. Thats where the glass meets the metal lens housing.

If Drum.. check the image "sensor" alignment X and Y and R for radius by trying to make it larger or smaller radius.




Dude, I have to admit... you ROCK.
I just opened PW4, And looked at the image. It felt like the X center is a little bit off the center of the image. So I moved the FisheyeImageEnclosing to the left alittle bit. And now There is NO PROBLEM at all :D

great. Thanks a lot :)


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2006-01-19
#9

It must be something to do with how the Agnos bracket locates... i just tried the same pano with 4+T and the first one was unusable and the second one was exactly correct.  I changed nothing at all on the camera or the mount/tripod, but once I had down the "up" on the 1st set, I had the turn the camera back down for the next 4. I suspect that when I did that I inadvertantly hit a sweet spot on the bracket and it worked. Its so unpredictable though? General Lee, do you notice similar results in that some are miles better than others for no apparent reason?

Andy


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2006-01-19
#10

Nodal Points "Correction" Entrance Pupils are NOT stationary within a Fisheye lens. It can vary up to 1/4" depending on the scene being shot. If objects in one shooting position are close to the lens when compared to the other shots in the panorama series you WILL always have some noticeable stitching errors if you are not helping the process along with control points. This is another reason why most images shot inside a room are taken from the middle and not to one side etc. (to keep equal distance! Thus keeping the nodal entrance the same as possible.) You will always notice these misalignments when objects are closer to the lens and not so when shooting outdoors where all things are basically in the distance.

Re-levelling each shot will add to this problem. Remembering we are talking about the Agnos panohead and it is recommended for good reason that you level position (1) only and then shoot your shots in rotation without adjusting levels.

Your nodal camera positioning should not move if you have the MrotatorT set up correctly. Though I do advise you use a Twin Axis Hot Shot Level to make 100% sure that your lens in not dropping. Again these levels are set only in position (1)  with is the 0 or 360 degree mark.

Regards, Smooth


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2006-01-19
#11

Hi Smooth

A really dense question here, but I'm good at those! I think you've hit on something I've asumed didn't matter - I just shoot four shots on the Agnos head starting from a random click point and just count round from there. Must the first shot always be at 0/360 for it to work out?  At the moment, I just start from the nearest click that suits which will hardly ever be 0/360 - although I do make sure its level for the first one?

Andy