The assembled panorama
tripod attachment
tripod attachment
How It’s Done
To produce my panoramic pictures I use a special attachment that is mounted on a tripod, which allows me to set the camera with the lens is exactly over the centre of the tripod. There is also fore and aft adjustment to compensate for the effects of parallax, which can cause problems when trying to align the images before stitching them together to produce the final picture. Once the camera is set up it is necessary to make sure the entire assembly is exactly level, to achieve this there is a spirit level on the tripod.
On the base of the panoramic head there is a numbered scale, from 1 to 16, which assists with getting the correct amount of overlap on each picture. For most pictures an overlap of between 20 & 25% of the total frame view is sufficient to ensure that there is enough common information within the pictures to make the alignment process easier. One of the drawbacks of this method can be seen in the Lower Slaughter and Wardens Way pictures where there is a distinct curve visible, this is a problem with being too close to the subject. To rectify this anomaly it would be necessary to move the camera from left to right, keeping it level, at a constant height and exactly parallel to the subject.
The camera can be moved backwards and forwards in the slot, which allows for accurate positioning to reduce the distortion effects that will occur if the lens is in the wrong position. The technical term is Nodal Point and this is the point inside the lens where the light rays cross over and invert the image on the digital sensor or film plane. The only way to arrive at the exact point is by trial and error using a near point such as a lamppost and a far point such as the edge of a building. The two are lined up in the left hand side of the viewfinder and then the camera is panned until the two points are at the right side of the viewfinder. If there is any mis-alignment this indicates that the camera/lens is not correctly positioned and needs to be moved either forwards or backwards by a small amount. The procedure is repeated until the objects are correctly aligned at each side of the viewfinder and the position of the centre of the tripod screw is noted down.
