The first inhouse test of the Watec camera established, that the small camera body got noticeably warm during operation. As the temperature of the ccd-chip is a significant source of noise, some experiments with cooling the camera body were made. To that behalf series of dark images were shot, with a small fan blowing ambient air (1°C) at the camera body.
The effects of the fan on the visibility of the "hot-pixels" was quite noticeable:
|The animated gif shows two images, which are each the median of a series of 35 dark images. Both series were taken with a unmodified camera, but in second series, a small fan created a continuous airflow across the camerabody.
The hot-pixels are noticeably dimmed through the cooling created by the forced airflow.
|The histograms of the dark images also show the effect of the cooling fan: The curve is shifted towards smaller brighnesses.|
|The diagram shows the standard deviation of all pixels, whose median brigtness values are identical. Here, no clear effect can be discerned.|
Go on to: Extended experiments with cooling