Hi Sharkbite
Reading your post gave me a feeling of dejavou
I had also used the exact webcam to take pics of the moon and had high hopes for planetary pics.
As you found out, there seems to be an autogain. Also, there is a button on the top of the webcam, which if you press, seems to cycle through some preset filters (goes green, dark, normal etc). Also, I couldn't get it to focus on the moon or anything for that matter. The moon was soo bright that it just looked like a white circle with a black background
Also, there was this annoying blue led that turned on as soo as I connected the usb cable. Had to solder that out
My first shot at a DIY webcam camera was frustrating and very painful