A virtual tour is a simulation of an existing location, usually composed of a sequence of videos or still images. It may also use other multimedia elements such as sound effects, music, narration, and text.
The phrase "virtual tour" is often used to describe a variety of videos and photographic-based media. Panorama indicates an unbroken view, since a panorama can be either a series of photographs or panning video footage. However, the phrases "panoramic tour" and "virtual tour" have mostly been associated with virtual tours created using still cameras. Such virtual tours are made up of a number of shots taken from a single vantage point. The camera and lens are rotated around what is referred to as a no parallax point (the exact point at the back of the lens where the light converges).
A video tour is a full motion video of a location, as if you were walking through a location. Using a video camera, the location is filmed while moving from place to place. Video tours are continuous movement taken at a walking pace.
The origin of the term 'virtual tour' dates to 1994. The first example of a virtual tour was a museum visitor interpretive tour, consisting of a 'walk-through' of a 3D reconstruction of Dudley Castle in England as it was in 1550. This consisted of a computer controlled laserdisc based system designed by British based engineer Colin Johnson.
One of the first users of a virtual tour was Her Majesty Queen Elizabeth II, when she officially opened the visitor center in June 1994. Because the Queen's officials had requested titles, descriptions and instructions of all activities, the system was named and described as "Virtual Tour, being a cross between Virtual Reality and Royal Tour." Details of the original project can be viewed online. The system was featured in a conference held by the British Museum in November 1994 and in a subsequent technical paper.
Methods of Creation
There are three popular ways of "stitching" virtual tours together.
Rectilinear stitching. This involves the rotation of a digital camera, typically in the portrait (up and down) position and centered directly over the tripod. As the operator manually rotates the camera clockwise, the camera stops or clicks into a decent at regular intervals, such as every 30° of rotation. The rotator can be adjusted by changing the position of "detent ring or bolt,"into another slot, to alter the interval of rotation: 40°, 60°, 90° etc.
If your camera lens supports a wider view, you could select a larger detent value (for example 60° instead of 30°). With a larger detent interval, fewer images are needed to capture a complete panoramic scene
Video-based virtual tours
With the expansion of video on the internet, video-based virtual tours are growing in popularity. Video cameras are used to pan and walk-through real subject properties. The benefit of this method is that the point of view is constantly changing throughout a pan. However, capturing high-quality video requires significantly more technical skill and equipment than taking digital still pictures.
Britain Express Virtual Tour of England
Dudley Castle c1550
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