data about the image, charge-coupled devices
(CCD) and complementary metal–oxide–
semiconductors (CMOS). Most digital cameras
use CCDs, but there are subtle but relevant
differences between how these two types of
sensors read and record data. CMOS chips
have a lower light sensitivity and are generally
more susceptible to noise, but use much less
power and are therefore well-suited to smaller
cameras. CCDs, on the other hand, are more
susceptible to becoming dusty, requiring more
frequent cleaning. A full discussion is outside
the parameters of this guide, but information
can be found on several web sites.^3
lE n S E S
Anyone who spends time looking at a variety
of panoramas will notice the difference between
those shot with an 8mm lens and those taken
with a 15mm lens. A smaller lens has a greater
field of view but objects will appear to be further
away and can have an apparent distortion on the
edges when a panorama changes view (although
this can be adjusted in post-production). Some
viewers have strong aesthetic preferences for one
or the other. There are implications to lens size
that may be relevant when choosing equipment.
The ability to zoom in on details in a panorama
is greatly affected by the lens. If the camera has
a CCD chip one square centimeter in size, for
example, the amount of detail captured on with
an 8mm lens will be far less than with a 15mm
lens, because the light captured from a much
greater field of view must necessarily fall on the
same space that captures more detail in a smaller
field of view with a longer lens. This translates
directly into the effective zoom achievable in
the final panorama. The trade-off comes with the number of images needed to capture
an entire sphere: an 8mm lens might do it in four frames, whereas a 15mm lens might
need twenty. (The terms used here, smaller/shorter and larger/longer refer simply to the
number of the lens; the actual physical size of the lens does not necessarily correlate).
- Wikipedia has entries on the CCD and CMOS chips. For basic information on digital cameras,
HowStuffWorks has a more general comprehensive entry (see Web References, below, for
URLs).
Figure 1. 35mm camera on a segmented
panorama tripod head. Photo by Tom
Watson.Figure 2. 35mm camera on a segmented
panorama tripod head, viewed from the
side. Photo by Tom Watson.