Re: Can digital capture do TIME exposures?

[Dan Scott]

On Saturday, January 11, 2003, at 09:57  AM, Jostein wrote:

...or approaching On Topic:

From "A guide for the use of CCD's: #1 Where to start", found by

google at:
http://www.starchaser-obs.com/Ot_art_1.htm

"Cooling is extremely important. If you use a CCD at room temperature,
thermal noise will add about 150 electrons per second per pixel. A
typical pixel has the capacity for around 150,000 electrons. This
means that in 17 minutes the CCD would be saturated by noise. For each
decrease in 13 degrees F. the production of thermal electrons
decreases by half. Therefore the cooler the unit, the longer the CCD
can be exposed before saturation by thermal noise. Most CCD's have
ThermoElectric cooling (TE). The best is liquid cooling, usually
liquid nitrogen."

Jostein

:-)

But you wouldn't have to cool your digicam to liquid nitrogen or liquid helium extremes to see an improvement would you? Wouldn't CO2 be sufficient for non-astrophotograpy uses?

Dan Scott (just guessing)