Philopod pitch variation - Revision history

Floz: Added link to video tutorial

2011-01-08T13:43:24Z

Added link to video tutorial

Bruno: add QTVR result

2007-04-21T20:06:47Z

add QTVR result

Erik Krause: 1 revision(s)

2007-03-21T18:09:03Z

1 revision(s)

Bruno: Added notes on using six shots

2007-03-21T18:07:00Z

Added notes on using six shots

Bruno: Added notes on using six shots

2006-12-11T10:58:09Z

Added notes on using six shots

Bruno: categorised

2006-07-25T12:53:21Z

categorised

Bruno: added final image

2006-07-21T15:52:51Z

added final image

Bruno: basic page on one philopod technique

2006-07-20T17:47:06Z

basic page on one philopod technique

New page

A [[philopod]] is a simple and portable alternative to a panoramic head. This
[[tutorials|tutorial]] covers just one way of working with a philopod to
capture a full spherical panorama.

These pictures are taken with a full frame [[Fisheye Projection|fisheye]] that has a 170 degree
vertical [[Field of View|angle of view]] when used in [[portrait]] orientation:

[[Image:Philopod-example-1.jpg]]

This means that it isn't possible to capture both the [[zenith]] and [[nadir]]
with a single row of shots - This would require both a lens with an angle
of view greater than 180 degrees and careful levelling of the camera.

However this isn't a problem if you manually tilt the camera up and down while capturing
the sequence, something that is hard with a tripod, but easy with a handheld
[[philopod]]. So the first and third shots are tilted down by 10 degrees or
so, capturing the nadir, and the second and fourth shots are tilted up 10
degrees to capture the zenith:

[[Image:Philopod-example-2.jpg]]

So when stitched together, there is a good amount of coverage of the entire scene:

[[Image:Philopod-example-3.jpg]]

One problem with this system is that the stitching seams run directly through
both the zenith and nadir. This causes problems for blending tools such as
[[enblend]], since they have no idea that this is an
[[Equirectangular Projection|equirectangular]] image and get the seams wrong as a
result. It is also difficult to hand retouch the poles for the same reasons.

The solution is to stitch the panorama in different orientation with all the
seams in the middle of the output where the equirectangular distortion is
minimal:

[[Image:Philopod-example-4.jpg]]

This is very quick and easy to do, just adjust the anchor image so the weight at the end
of the philopod is in the centre of the output. This has another useful advantage -
The panorama is now completely self-levelling since the philopod forms a plum-line, so
there is no need to set [[vertical control points]] to level the scene.

The final step is to flip the panorama back to a level orientation, just load
it into one of the [[GUI front-ends]] as an equirectangular input image with a pitch of
-90 degrees and ''stitch''.

← Older revision		Revision as of 13:43, 8 January 2011
Line 58:		Line 58:

	[[Category:Tutorial:Specialised]]		[[Category:Tutorial:Specialised]]
		+
		+
		+	=== Links ===
		+
		+	* [http://www.youtube.com/watch?v=ouOEM4cKKGc Video tutorial demonstrating this technique]

@@ Line 43: / Line 43: @@
 The final step is to flip the panorama back to a level orientation, just load
 it into one of the [[GUI front-ends]] as an equirectangular input image with a pitch of
--90 degrees and ''stitch''.  Here is the result in [[Mercator Projection]]:
+-90 degrees and ''stitch''. Here is the result as a QTVR:
-[[Image:Philopod-example-5.jpg]]
+<pano file="Philopod-pitch-variation.mov" width="600" height="450" scale="tofit" controller="true" cache="true" />
 === Notes ===

← Older revision		Revision as of 18:07, 21 March 2007
Line 57:		Line 57:
	''up, down, down, up, down, down'' sequence instead.		''up, down, down, up, down, down'' sequence instead.

−	~~[[Category:Tutorial]]~~[[Category:Tutorial:Specialised]]	+	[[Category:Tutorial:Specialised]]

← Older revision		Revision as of 10:58, 11 December 2006
Line 46:		Line 46:

	[[Image:Philopod-example-5.jpg]]		[[Image:Philopod-example-5.jpg]]
		+
		+	=== Notes ===
		+
		+	This technique isn't limited to four shots with an ''up, down, up, down'' sequence. Lenses
		+	with a narrower [[Field of View\|angle of view]] or difficult scenes might require six shots at 60 degree
		+	rotation.
		+
		+	In this six shot case, the obvious sequence of ''up, down, up, down, up, down'' generates
		+	complex seams that are difficult to disentangle, I get better results with an
		+	''up, down, down, up, down, down'' sequence instead.

	[[Category:Tutorial]][[Category:Tutorial:Specialised]]		[[Category:Tutorial]][[Category:Tutorial:Specialised]]

← Older revision		Revision as of 12:53, 25 July 2006
Line 46:		Line 46:

	[[Image:Philopod-example-5.jpg]]		[[Image:Philopod-example-5.jpg]]
		+
		+	[[Category:Tutorial]][[Category:Tutorial:Specialised]]