Using this method photographs are taken by holding the camera in front of the eyepiece. With this method both the camera lens and the eyepiece are used to focus the image on either film or digital chip.This can be an easy method for capturing bright objects like the moon or planets.

The thing to watch out for is vignetting. Certain eyepiece and lens combinations can cause darkening of the edges. If your camera has a zoom you may see this happen if you zoom the camera in. Vignetting can be reduced by keeping the camera lens very close to the eyepiece lens.

Several eyepiece manufacturers make adapters specifically for use with their eyepieces.

This is often used in combination with a prime focus t-adapter. A focal reducer as it's name suggests reduces the focal length of the lens system in a telescope .A Focal Reducer lens is used mostly with a CCD or film camera. A focal reducer works by concentrating the light cone produced by the scope into a smaller, yet brighter circle. Because the light cone at focus is actually smaller and the detector stays the same size, the field of view also increases. A wider field of view allows relatively large objects to fit within the frame of a tiny CCD chip.

Because the focal ratio of the lens or telescope is reduced, the time required to image an object is also reduced. When imaging faint objects, the integration time is a significant factor, and a significant reduction is achieved by employing a focal reducer.

This method can be used to take wide field pictures. This is a great way to capture images of the milky way. The camera is mounted on a telescope which is used for tracking.

Obviously the requires a telescope mount that can track. Guiding software is also useful to accurately keep the image in place.