Magnifying Chamber

a telescope accessory that makes it possible to obtain an image of a heavenly body that is larger than the image in the focal plane of the telescope objective. In visual observations of the sun the eyepiece is separated from the focal plane of the objective by a distance that is greater than the focal length of the eyepiece but less than twice that focal length. The real image of the sun produced by the eyepiece is projected onto a white screen fastened to the telescope tube.

Photographic magnifying chambers are usually called eyepiece cameras.