Digital noise 57
Noise comes from many sources
Digital noise from sunspots? Yup. Scientists, especially astrono-
mers, analyze hot pixels to measure the effects of solar particles
and cosmic rays on digital images and you could extrapolate that
sunspots indirectly cause hot pixels due to the solar particles and
cosmic rays they generate. Closer to earth, there are other elec-
tromagnetic sources that cause noise in your digital images. Here
are some situations that you should avoid:
- Photographers should avoid placing external battery packs
close to their digital cameras. Some of these packs contain
transformers that raise voltage levels for faster fl ash recy-
cling and emit electromagnetic interference at the same
time. This can result in severe degradation of digital image
quality with heavy banding effects. In such cases, the best
work-around is to carry the battery pack on a belt or a photo
vest while connecting it to the fl ash unit via a cable. - Photographers should also avoid taking pictures close to
other strong sources of electromagnetic energy. For example,
it’s quite common to see heavy banding in digital images
shot from the observation deck at the Empire State Building
in NYC due to the presence of strong antennas at the top
of the building. Similar situations can occur in sports
photography when the photographer is standing too close
This photograph was made with a Leica D-Lux 2 point-and-shoot camera. Exposure was 3.2 seconds at f/6.3
at ISO 80. (Joe thought it was set for 800, proving that even guys who write books should use a fl ashlight
at night to check their camera settings.) Although not tack sharp, the photo is almost acceptably sharp enough
due to the D-Lux-2’s built-in image stabilization, which, in this particular rocky boat situation, was probably
a better bet than a tripod. © 2006 Joe Farace.