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Old 10-02-2009, 07:56 PM
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gregbradley
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Quote:
Originally Posted by Peter Ward View Post
1) On class 2 (or lower) devices you can certainly see these...but that's why I use a class one chip: it dosen't have hot columns.

2) The hot columns I have seen fade with delta T....but...and here's the rub.... if you calibrate the data accurately...hot/dark pixels and columns disappear.....unless you have defect on the chip.
I have seen it one a class 1 chip.

Theoretically the line will go and often does but mysteriously I found it also often did not. Its also not a column defect as you know - there is a paper on it on the SBIG site - its caused by a hot pixel and the readout process of KAI family chips.

They can also appear later on as a CCD deteriorates over time.

Greg.
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