panorama software,virtual tour software
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Joined: 2006-05-23
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2006-05-23
#1

MrotatorTCPS and nodal point help

I want to take 360s including floor and ceiling:

I bought the Sigma 8mm EX DG

Will probably buy the Nikon D50

Will probably buy the MrotatorTCPS

So I read that the worst part is finding the nodal point.

1. Is there a tutorial around for this procedure?

2. Instead of the MrotatorTCPS,  is there a camera specific setup for the D50 that would eliminate this nodal point problem?

 

thanks,

Tony


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Joined: 2005-09-16
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2006-05-23
#2
Three leap to mind, the ipix grip which you will never find, the 360precision head which is custom made for each setup but costs over a thousand dollars or a bophoto grip which is rather inflexible and possible not as sturdy but an entertaining gimick
see http://tinyurl.com/ehqn2

but all in all I wouldn't worry that much its fiddly but not the hardest thing in the world. Its pretty much near the gold ring on the lens and there are lots of tutorials around. And of course a proper head gives you more flexibility for the future. If you really can't face the choices just get a panosaurus off ebay for 70 dollars, a plastic equivelent head, and experiment till your confident in what you are doing.

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Joined: 2002-06-12
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2006-05-23
#3

If you have not already done so.. you might consider visiting this page

http://www.360texas.com/tips/nodalptscanon.htm  Finding nodal point with a dSLR is rather easy.  Probably takes about 5 minutes.  The gold ring on the Sigma 8 lens is a good starting lens location.  Put the gold ring on the lens directly over the top of your tripod point of rotation.

Send Agnos an email and mention the D50 and Sigma 8 and ask him for his recommendations.


/s/
Dave
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Joined: 2002-11-23
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2006-05-24
#4

Here is my tips on how I set the nodal point 100% correctly on the Sigma 8mm on a Agnos MrotatorTCPS panohead.

From early 2005:

I have a method that works quite well it entails some thought but works 100% everytime.

Now this is my method worked out by me and is suited to the MrotatorT series rotators using a Sigma 8mm fisheye.

See if you can follow me as I haven't as yet built the web page or taken any photo's of this method.

  • Turn your MrotatorT upside down and using a scribe or sharp blade run around the plate (with the bubble level) and mark it so when you remove the bubble level plate from the actual rotator base (3 hex/Allen screws) when upside down you will see a complete perfect circle.
  • Now what I did was find the centre of this circle with some vernier callipers and two X scribe marks. "Dead centre of the circle"
  • Using a centre punch being extremely careful mark for accurate hole drilling. then drill a small hole (about the size or smaller then the three hex bolt holes).
  • Now, put it all back together we now know "exactly" where centre really is! This is the centre line of the tripod and where the nodal point "must" line up too in both X and Y coordinates.
  • Still with me? Easy... OK now I used a length of 20lb 0.45mm fishing line and made a nice circle loop around the Sigma 8mm Fisheye lens with only "minimum" amount of slack (bugger all). When you fit the fishing line to the lens you will be amazed to see that the "Gold Ring" (the commonly know position of the nodal point) has a slight "detent" and the fishing line fits "beautifully" within the detent groove.
  • Now we need a "Plumb Bob" I used a 150gram steel bugger. Now your getting the picture aren't you? BUT WAIT! You need to attach it in a special way to your fishing line loop you made earlier. It "MUST" be attached with it's "own" loop of fishing line. These "TWO" separate loops are very important as they operate independent of each other and must have minimum friction. 
  • Now that done, you set the tripod up on "perfectly level" flooring and make your adjustments to the X and Y of the camera fitted to the MrotatorT until the "Plumb Bob" points exactly to the centre of the hole you drilled in the MrotatorT bubble level plate. Once you have achieved this I will tell you that you are as close as possible to the nodal point as you will ever get using a Sigma 8mm Fisheye Lens. Remembering that the nodal point is "NOT" in a fixed location inside a fisheye lens when being rotated. But the nodal movement is minimal.

I have since thought of some improvements to this system I worked out but I will save them for the day I publish my web page. The reason I have not added these improvements to my own set up is because once I set mine I have been happily shooting panoramas and didn't see the point in upsetting a perfectly good nodal point position only to help others and cause myself the extra work.

I don't offer a 100% guarantee. But for me it has been the "Most" successful, least "Painful" nodal point set up I have ever done! No need for numbers or taking a thousand photo's and stitching and checking etc.

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Joined: 2006-03-07
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2006-06-02
#5

Smooth,

If I'm reading your instructions right, Agnos now puts a hole where you drilled yours. It sits right inbetween all three hex heads and is the center of rotation.

360, what head is that? If its the TCPS, they've changed the design considerably.


Ain't nothing friendlier in the world than a muddy wet dog.
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2006-06-02
#6

OK, Agnos must have taken onboard the centre hole design. That hole is the "very centre" of the tripod and this is the place you must get the nodal point directly over the top of. (In both vertical and horizontal axis) This is the point where the "Plumb Bob" point will point too using my instructions above.

The panohead Dave from 360Texas shows is a very old Kaidan Kiwi and should not be confused with what we are talking about with the Agnos MrotatorTCPS. Dave was just showing you where the nodal point position is approximately. It matters not what panohead you use the nodal point is always the same. Correct is correct and wrong is always wrong.

Good luck.

Regards, Smooth


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Joined: 2002-06-12
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2006-06-02
#7

I agree.  Nodal point or entrance pupil is a function of the lens not the camera.


/s/
Dave
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