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An idea for the automatic pano head

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Re: An idea for the automatic pano head
« Reply #20 on: 22 / December / 2008, 11:59:43 »
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One other thing to consider is that you do not want to rotate the camera around its tripod socket, but rather around the nodal point of the lens to eliminate optical abberations from your panoramas. :(

HTH,
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Re: An idea for the automatic pano head
« Reply #21 on: 23 / December / 2008, 12:58:36 »
One other thing to consider is that you do not want to rotate the camera around its tripod socket, but rather around the nodal point of the lens to eliminate optical abberations from your panoramas.

Not so.

The nodal points (of which there are two) are irrelevant.
This is the great myth of panorama photography.

You rotate the camera around its entrance pupil (of which there is just one), as that is the centre of perspective of the optical system.


David

Re: An idea for the automatic pano head
« Reply #22 on: 23 / December / 2008, 17:06:14 »
Nodal point, entrance pupil, whatever. For my camera, the tripod screw is directly below the lens, and my mount holds it sideways (in portrait mode) in a position that's close enough. Tilt and pan parallax are small enough to ignore except for extremely close-up features.

I once read a no-math, empirical way to find the "optical center of rotation" for your camera or rig. You take your rig outside and plant it a couple of feet from a chain-link fence, with something obvious (like a building) far away on the other side of the fence. Looking through the SLR viewfinder or the LCD display, identify a spot on one side of the image where a crossing in the fence is right next to a feature on the building. Now pan the camera so the crossing-and-feature combo is on the other side of the image. If the relative positions of the wire crossing and the building feature do not change, you have found your optical center. If they do change, adjust your rig and try again: if it gets worse, adjust in the other direction. Repeat until satisfied. Perfection won't matter unless you do a lot of interior panos with close-up objects. The same trick works for tilt as you move your crossing-and-feature from the bottom of the image field to the top (or vice versa).

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Offline fvdk

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Re: An idea for the automatic pano head
« Reply #23 on: 23 / December / 2008, 18:14:34 »
Nodal point, entrance pupil, whatever. For my camera, the tripod screw is directly below the lens, and my mount holds it sideways (in portrait mode) in a position that's close enough. Tilt and pan parallax are small enough to ignore except for extremely close-up features.

I once read a no-math, empirical way to find the "optical center of rotation" for your camera or rig. You take your rig outside and plant it a couple of feet from a chain-link fence, with something obvious (like a building) far away on the other side of the fence. Looking through the SLR viewfinder or the LCD display, identify a spot on one side of the image where a crossing in the fence is right next to a feature on the building. Now pan the camera so the crossing-and-feature combo is on the other side of the image. If the relative positions of the wire crossing and the building feature do not change, you have found your optical center. If they do change, adjust your rig and try again: if it gets worse, adjust in the other direction. Repeat until satisfied. Perfection won't matter unless you do a lot of interior panos with close-up objects. The same trick works for tilt as you move your crossing-and-feature from the bottom of the image field to the top (or vice versa).


Here is a very nice tutorial which shows this principle and also shows another method.

FINDING THE NO-PARALLAX POINT

Frans


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Offline fbonomi

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Re: An idea for the automatic pano head
« Reply #24 on: 23 / December / 2008, 19:28:16 »
This is the great myth of panorama photography.

thanks, Microfunguy!
when reading that stuff about nodal points, there was always something that unsettled me, but  I never thought about it properly...
After reading that simple phrase, everything suddenly becomes self-evident!

It will probably be less self-evident after reading the very complete 19-pages article linked above:-)

Re: An idea for the automatic pano head
« Reply #25 on: 23 / December / 2008, 20:07:31 »

It will probably be less self-evident after reading the very complete 19-pages article linked above:-)


I've read a good part of that article and that is a true statment. lol
« Last Edit: 23 / December / 2008, 20:09:13 by Neanderthal_Man »
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Re: An idea for the automatic pano head
« Reply #26 on: 24 / December / 2008, 22:02:25 »
...you do not want to rotate the camera around its tripod socket,...

HTH,

Which is the problem I'm seeing in these rigs, so I'm glad that there has been additional input and clarification of this point. :xmas
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Offline ditch

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Re: An idea for the automatic pano head
« Reply #27 on: 30 / December / 2008, 10:46:53 »
dang! that is awesome work dsvilko!


 

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