Help with focus issue

[Mick1]

I've bought my self a ZWO ASI120MC camera (attached to a 102 f9.8 refractor) and tried it out last night but all that was displayed on my laptop was blackness.

I set up the camera in daylight and focused on a tree top some distance away and got an image no problems. But when it came to imaging Jupiter nothing, and I moved the focus to both extremes of travel. I attached the camera both after the diagonal and at the end of the focus tube, also with a 2 x barlow as I understand that this can help as well.

Would I need an extension piece before the camera so the image can be brought into focus. If so how would I determine the length of the extension piece that I would need?

[PKay]

Hi Mick

I had the same thing happen. It turned out the small target was not in the field of view.
If you can get focus in the day, leave it at that.
Then use the moon (a bit harder to miss).
Yes I had to fiddle with spacers to get focus ( i used a 2X barlow with the lens removed).
Then fine tune your finder scope.