Amp Off Test on SC3 modified toucam webcam


Recently I have been experimenting with direct bias injection amp off methods on my SC3 modified toucam.

Due to the increasingly long evenings and poor weather, I've not been able to try this out under the stars. On the night of 7th May 2005, after spending the night playing with the Artemis CCD camera, I performed a quick test with the SC3.

M3 Globular Cluster

Globular Clusters are good targets when you are worried about dynamic range. To make sure I reached full saturation, I imaged for 10 seconds at maximum gain. To add some spice, my laptop parallel port stopped working, so I had to start imaging on the guiding computer, so no guiding. However, for the purposes of this test guiding is not required.

First some raw frames.

Amp On. 10s single raw frame.

Amp Off. Direct Bias Injection. 10s single raw frame.

Then I stacked 20 frames from each and strongly histogram stretched the result.

Amp On. 20x10s Histogram Stretched.

Amp Off. Direct Bias Injection. 20x10s Histogram Stretched.

Bear in mind that I'm sure some web browsers scale images - I suggest you save these an compare them locally on your computer.


I cannot detect any change in dynamic range. Amp Glow is removed with the amp off circuit. This is a good initial result - more testing is required!