My dark-frame sequence [below] demonstrates how rapidly noise builds up in consecutive shots, and how turning off the camera mitigates this problem somewhat." Kovacsy's first image, taken at an ambient temperature of 66° F, is nearly free of noise. Turning off the camera for 10 minutes produced an image as clean as the first."Note how even the 10th image taken at 40° F has less noise than the second image taken at 66° F," he adds.
Note, however, that high-end professional digital SLR cameras feature an interchangeable lens mount so you can use standard T-ring adaptors to attach the camera directly to the telescope.
The frigid ambient air of winter cools a digital, astrophotography camera naturally.
The labels give the ambient temperature in Fahrenheit and the number of successive frames taken.
Because of their inherent dimness, deep sky objects require exposures of up to several minutes.
You need a way to keep a digital camera relatively cool in order to increase its exposure time and therefore, enhance its sensitivity to faint objects and its overall image quality.