Equipment for Taking Panoramic Photos
Taking good stitched panoramas requires a few pieces of special equipment. Obviously you need a camera, and the good news here is that most digital cameras, even inexpensive ones, nowadays have all the necessary hardware. Unfortunately not all of them have the right software. You also need something to hold and rotate the camera precisely. This can be done effectively by hand, if you're either very careful about how you hold it or prepared to do a lot of post-processing on your images.
A defining feature of modern cameras, at least the ones that are designed to be easy to use by most people, is automatic control of most or all of the parameters required to take pictures. You don't have to rotate focus or aperture rings or select shutter speeds and flash power like all photographers a few short decades ago had to do. Aside from adjusting focal length (zoom), cameras now come with sensors and electronics that can analyze a scene and configure themselves for a well-exposed, in focus snapshot in a split second. While nobody in there right mind is going to argue that this technology in and of itself is a disadvantage, you need an alternative when you want to taking panoramas.
In a stitched panorama, several exposures taken with the camera facing in different directions are combined into a single image. Where a pair of photos overlap, any objects in that region need to appear with the same brightness in both images. This means that both pictures (and by extension, every one in the entire set) need to be taken with the exact same exposure. On a manual camera, this isn't a problem: you simply set your exposure settings at the beginning of the sequence and make sure not to change anything until you're done with all the exposures. But when you point an auto-exposure camera in a different direction, the new scene will invariably have a different metering result, and the exposure won't match the last picture you took. To prevent this, the camera has to be told to keep the same exposure settings when taking multiple pictures.
There are many point-and-shoot digital cameras that can be used for taking panoramas. Two that I have used are the Olympus D-520 Zoom and Canon Powershot A520. The panorama function on the Olympus (a relic from 2002) provided a simple exposure lock and displayed guidelines on the screen to help composing shots with proper overlap, and was only available when using one of Olympus's own (overpriced) SmartMedia cards. The Canon has a more advanced panorama mode: in addition to being storage-medium-vendor agnostic, it overlays part of the last picture next to the current viewfinder image on the screen, allowing mostly foolproof composition. This camera also has a full manual mode (including manual focus control) that also works well for panoramas, especially in extremely low light where the panorama mode never sets the shutter slower than about 1/8s.
Using an SLR camera is the traditional way to shoot panoramas. Any DSLR will let you manually control or lock all exposure and focus settings, although most don't have a dedicated panorama mode.
A tripod should be used whenever possible when taking panoramas. Ths is because every picture must be taken with the camera in the same location. If the camera is allowed to move, rather than just rotate, object in the foreground and background will shift relative to each other; this is called parallax error. Handheld panoramas therefore work best for things like distant landscapes with no foreground. Unfortunately, a standard pan-head tripod usually will only reduce but not completely eliminate parallax.
Specialized Panorama Heads
A panorama head is a bracket that attaches on top of a tripod and holds the camera and provides control to shift and rotate it. The shift adjustment is used to position the camera so that the lens's entrance pupil or "no-parallax point" is exactly at the center of rotation. The rotation controls usually include angle measurements to help spin the camera by the exact amount necessary between exposures.
A logical extension of a panorama head is to add motors on one or both axes to rotate the camera, and a computer to automatically control the rotation and the camera's shutter. There are several home-made versions of these as well as at least one commercial model: