A cheap adapter can be used to connect a mobile phone to a telescopic eyepiece.
This allows video clips to be captured through the telescope.
While the clips are pretty basic, stacking software can be used to stack the individual frames to produce some nice Moon and planetary images.
The adapter is basically a piece of plastic with a hole in. The phone can be clipped onto one side and slid into place so that the lens looks through the hole, while the eyepiece is clipped in on the other side opposite the hole (a bit of PVC tape around the eyepiece barrel gives the adapter a good grip).
With autofocus disabled the mobile camera is manually set to focus at infinity.
With the phone and eyepiece then in place on the telescope and the telescope pointing at an object of interest the focus is then fine tuned on the mobile screen using the telescope focusing control.
This is afocal astrophotography.
(Obviously image brightness can also be adjusted by altering the relevant camera settings.)