...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 :-) ----- Original Message ----- From: "T Rittenhouse" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, January 11, 2003 2:35 AM Subject: Re: Can digital capture do TIME exposures? > http://www.skinsite.com/info_liquid_nitrogen.htm > > You could have done the google search yourself you know. > > Ciao, > Graywolf > http://pages.prodigy.net/graywolfphoto > > > ----- Original Message ----- > From: "Feroze Kistan" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, January 10, 2003 6:28 AM > Subject: Re: Can digital capture do TIME exposures? > > > > What is the purpose of liquid nitrogen and where is it used? > > Feroze > > ----- Original Message ----- > > From: "T Rittenhouse" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Friday, January 10, 2003 1:50 AM > > Subject: Re: Can digital capture do TIME exposures? > > > > > > > Yep, a little liquid nitrogen will do wonders. > > > > > > Ciao, > > > Graywolf > > > http://pages.prodigy.net/graywolfphoto > > > > > > > > > ----- Original Message ----- > > > From: "Jostein" <[EMAIL PROTECTED]> > > > To: <[EMAIL PROTECTED]> > > > Sent: Thursday, January 09, 2003 11:40 AM > > > Subject: Re: Can digital capture do TIME exposures? > > > > > > > > > > I think the ability to do long exposures depends on how much thermal > > > > noise the chip produces, and how well it can separate noise from > > > > signal. > > > > > > > > Dunno the current tech on any particular camera, but I know astro > > > > photographers have long embraced digital. However, I think their > > > > devices have some serious cooling systems. > > > > > > > > > > > > >
