Hi Bob.. The white blob thng is very common with new users of WebCams. I had the same trouble as you also. If the moons aroung Jupiter are nice and clear but Jupiter is a White blob it is not a focus problem. What you are getting is and over exposed image. The Webcam is very sensitive to light so you need to reduce this by doing the following. You need to go into the driver settings for the Webcam. This can often be done by clicking on the Philips icon in the taskbar or in the Webcam settings in the recording software you are using like K3ccdtools etc. You will need to uncheck the auto settings for the webcam and adjust the camera settings your self. When you get in thier this will all make sense. Lower the frame rate to around 10 frames per second and then slide the gain down to almost no gain. do it slow and you will notice that Jupiter will show detail now but will be dark. Set the Exposure to around 1/25 sec and just increase the brightness a little. I am sure you will now see a better image and no bright white blob. Play around with these settings untill you get the result you are looking for. I hope I have been some help. I am also new to this myself and this is how I have got better results. Others with more experience may also add some other or even better advice. You are on the right track to getting results.. I got my first good result with Jupiter last week doing what I have explained to you. Good Luck and let me know how you go..
Cheers
Mardy