70 degrees Fahranheut versus 7 degrees Fahranheit ambient temperature
Dark Current Noise
The following screen dumps are of dark frames using QCV2 which allows long exposure times on the greyscale quickcam. This shows the effect of cooling on dark current noise which is greatly reduced by lowering the temperature of the CCD chip.
On the left are screen dumps at 7 F and on the right at 70 F:
60 second exposure:
120 second exposure:
Antiblooming was disabled for all images. The dark current noise is so much greater on the 120 second 70 degree F image that bleeding resulted. This demonstrates the reduction of dark current noise by cooling of the CCD chip. The source of the herringbone interference pattern in the 120 second 70 degree image is being studied.
UPDATE 1/17/00 - Herringbone problem was caused by power outlet strip with indicator light.
Here is an image at 300 seconds exposure and at -4 degrees fahranheit with the power strip removed.