Filling a frame with a small section of the Moon requires lots of focal length, more than most telescopes otter. The answer is eyepiece projection. Many camera adapters come with an add-on extension tube that accepts an eyepiece, although Schmidt-Cassegrain telescopes require a separate adapter called a tele-extender.
The eyepiece projects a highly magnified view of the Moon onto the film.
Eyepiece projection is also essential for photos of planets. Without the extra magnification, their disks will be far too small to show any detail.
Lunar close-ups and planet portraits usually require taster
ISO 200 to 400 film and exposures of to 4 seconds. To make the exposure, hold a black card over the front of the telescope, open the camera shutter on Bulb, then flip the card away and back again.
Without this "hat trick," your photographs may be blurred by the slight vibration of the camera's own shutter.