For astrophotography using 'medium size' land telescope at good location,
How many time longer exposure, in view of boosting the system's ability to photograph even darker objects, can one gets from cooling down digital camera sensor chip?
Is there a 'sweet spot' temperature where most thermal related noise is suppressed and further lowering of temperature yields litter extra benefit.
What is the ball park temperature for low (amateur), medium and high (professional) grade cooled camera?
Web search shows that Peltier electric cooled camera works at around "minus a few tens degrees centigrade". Does the really professional one cool to more extreme level, somewhere close to liquid nitrogen temperature?
- Does CCD, CMOS or other sensor have different 'sweet spots' temperature?