Mar 6, 2003 Ghost Image
- If the cloud was there, it should have showed up on the images that I took the next night [Mar 7] as well.
- The CCD controller can give a "short circuit" signal or as they call it a reset signal to erase CCD contents. It's more like a capacitor
discharge. This short circuit is based on transistors, which have resistance. Its more like a resistor than a short circuit wire. It
takes time to discharge. The default timing is enough for most applications. It must be a controller malfunction, and/or the user
before me took a really very long bright exposure. I think its the first, a controller malfunctioned and didnt apply reset as it should
be or didnt apply a long enough rest signal, or the reset signal was not received correctly by the CCD (most likely cause). Electric
noise can affect controllers signals, and thus misinterpreted by the CCD electronics.
- One way to avoid this is by taking a short dummy image and through it. This does not happen very often.