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A comment on 1060-hour image of the Large Magellanic Cloud captured by amateur astronomers. Parent comment

Re:1060-hour image of the Large Magellanic Cloud captured by... by munificent on Monday April 15, 2019 @01:25AM (#19663281)
> Also, digital camera sensors tend to get noisy with longer exposures due to heat build up around the sensor (a problem film cameras do not suffer).

Maybe worth pointing out that film has its own issues with long exposures, though. If I remember right, film's response to light isn't strictly linear with exposure time so you get less and less useful additional exposure as you expose longer.

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Re:1060-hour image of the Large Magellanic Cloud captured by... by _ph_ on Monday April 15, 2019 @03:33AM (#19663741)
Yes, with film there is the Schwarzschild-effect which causes the sensitivity and the color reaction vary with the exposure time.

While digital camera sensors usually pick up noise for long-time exposures, this is less an issue for astronomical cameras, because they fight this noise by cooling the CCD-chip. Usually the chip is cooled via a Peltier-element to temperatures below -20C, where thermal noise is very low.

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Re:1060-hour image of the Large Magellanic Cloud captured by... by gomox on Monday April 15, 2019 @09:49AM (#19665259)
The aforementioned effect is termed "reciprocity failure".
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