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A comment on Depth of Field. Parent comment

Re:Depth of Field by pjc50 on Sunday March 27, 2022 @01:24PM (#30822058)
The noise is coming from inside the sensor: https://en.wikipedia.org/wiki/Johnson%E2%80%93Nyquist_noise

Cryogenically cooling helps, but since you can't hit absolute zero you can't entirely eliminate it.

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Re:Depth of Field by passivate on Sunday March 27, 2022 @01:41PM (#30822226)
There is read noise from downstream electronics converting photons to electrons, but the "shot noise" is a property of the photon stream and will be present regardless of how much we improve the electronics. Cooling the detector won't help there.

https://en.wikipedia.org/wiki/Shot_noise#Optics

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Re:Depth of Field by alecbz on Sunday March 27, 2022 @01:39PM (#30822209)
Right, what I was missing was why how far the source of the light is effects how much the noise matters, but the inverse square photon concentration explains that.
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