 noise,
which is why they are cooled to extremely cold temperatures.
Most cameras designed for amature astrophotographers are also cooled,
but typically only 10 - 30 degrees C below ambient temperature.
</blockquote>
<p>
Many people find noise distracting, and a good way to decrease it is to subtract
it from a captured image.
A picture that contains your desired object, e.g., night sky, and noise is called a
<strong>light frame</strong>.
A picture with just the noise (like the picture above) is called a
<st