Creating a 360 degree VR (1)

Table of contents

Preparation

PTGui and Autopano

Fine-tuning with PTGui

The zenith-image

Assembling the images

Creating the QTVR

Thanks to the following people who helped me improving this tutorial:

John Houghton
Erik Krause
Brooks Leffler
George Row
Roberto Gómez Torres
Jim Watters

Creating a 360 degree VR (1)

Go here if you look for an updated tutorial for PTGui V5 and above!

This tutorial describes a workflow for creating interactive 360x180°-Panoramas by using fisheye-images as input and Quicktime VR as output.

I assume you are already familiar with basic stitching technologies of Panotools/PTGui.

Software:

Following Software is used during this tutorial. You can click on the Hyperlinks to follow to the homepage of the respective Software Developer/Company:

Panotools and PTGui
Autopano
Enblend
For retouching the images: A program that is able to work with layers, e.g. Photoshop or Gimp
Previewing the Panoramas: PixScreen Lite
Creating the final Quicktime VR: PanoCube (Plus)

Due to legal reasons the pre-installed Version of pano12.dll is limited to 120° FOV. Please use an adapted version of the DLL to get a wider FOV. A good place to start is sourceforge.net.

You will occasionally see such green boxes in the text. The text inside will discuss special topics which are not relevant for understanding the basic process.

Please note that the methods discussed here are only a subset of techniques for creating a VR-Panorama. You are invited to also research your own methods - and not only follow this tutorial word by word...

Part 1: Equipment and Preparation, The Nodal-Point

What is the nodal-point?

Close one eye and look at the edge of your monitor. Now rotate your head a little and keep looking at the edge of the monitor. You will notice that the monitor's edge is changing its position relative to the background.
If you would meet the nodal point, the objects would not change their relative position. This is why a nodal point adapter is used in panoramic photography. It helps merging images because every part of your scene looks the same on every photo you take for your panorama.

Here are some good sources how to exactly define the nodal point of your setup:

Nodal Point determination by Ben Kreunen
Nodal point (esp. for Sigma 8mm fisheye) by Michel Thoby
"The grid" by Alain Hamblenne

Why Fisheye?

There are 2 different methods of taking photos for a full 360x180°-image:

A common wide-angle lens with 28-35mm demands about 30-50 photos that have to be stitched afterwards! Using a fisheye reduces the number of photos down to 3-8. Especially in scenes with moving objects or handheld photography you will notice the advantages of 180° lens.

What are the basic techniques when using a fisheye?

With tripod:

If you want to minimize the effort and trouble in creating your VR, use a tripod and a nodal-point adapter. There are also professional ones available from Manfrotto, Kaidan, Novoflex and others.

For starters: You don't have to buy a high-priced adapter to begin. With a little effort you can also build your own one. Here are some basic examples:

Metz-Rail

Metz Flash-Rail for the camera in landscape format. Your tripod's camera screw must lie over the axis of rotation of the tripod.

Pro: The flash-rail is so small - you can carry it with you without problems.

Con: You can rotate around the nodal-point but you cannot tilt the camera!

Aluminium-Adapter

Self-made aluminium adapter with a panorama-plate from Novoflex. See here for more details.
Pro: You can also tilt the camera around the nodal-point.

Con: Not very stable.

Without Tripod:

The basic idea is to rotate yourself with the camera around the nodal-point. Here are some good tricks to accomplish this:

The Philopod:
What you need is a cord and a small weight. A small bubble level will also help.
Fasten the cord on your lens - at the position of the nodal-point. A fisheye lens has the nodal-point inside the lens (With the well-known Sigma 8mm for instance you can use the golden ring as a hint for your nodal-point)

Let the cord including the weight hang down. Now you have a position on the floor where to turn around.

John Houghton has expanded this idea with a template that you can lie down on the floor.

You may also take a look at my handheld photography tutorial.

When you have done your first photos for a VR-Panorama - Your will be ready to advance to...

Part 2: PTGui and Autopano