ST-7 Dark Current as a Function of Temperature

A series of ST-7 Dark Frames are shown here to illustrate the effects of lowered temperature on Dark Current.

This image is composed of swaths from four different dark frames of 20 minutes duration.

In the winter when outdoor temps run around +10F I am able to run my ST-7 at almost -40C

In the summer when outdoor temps run around +40F I am often unable to reach -20C

The dark noise is the primary limitng factor on the ST-7's ability to run for long exposures and I am actively seeking ways of cooling the ST-7 in order to be able to reach a temp of -40C all year around. The addition of an extra TEC stage seems promising.

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