Geoscope Standard mirror stereoscope
The Geoscope Standard model is a mirror stereoscope for viewing side-by-side prints in the parallel format such as aerial photographs and supports images separated by around 9 inches and the large mirrors provide relative good coverage. The Geoscope features chrome plated first surface glass mirrors that present very clear images without ghost reflections or chromatic aberration (color fringing). The mirrors are set at a fixed angle around 46 degrees and are parallel. An optional 1.2x magnification eyepiece is included. The Geoscope has a clever folding design and the large mirror rotate and fold into the body of the viewer for compact storage, and a carry case is supplied. A parallax wedge is also included along with instructions on its use. The viewer is made from tough and durable ABS plastic.
The Geoscope Standard model by Stereo Aids in Australia has a relatively wide separation between the mirrors making it suitable for viewing images with a separation of between 8.25 to 10.25 inches and thus supporting images between 8.25 to 10.25 inches wide. The Geoscope has relatively large mirrors offering relative good coverage of roughly 6.5 inches wide and 8.5 inches high without the eyepiece and coverage of 5.5 inches wide and 8.25 inches high with the included 1.2x magnifying eyepiece. High quality first surface chrome mirrors are used that provide crystals clear images. The viewer is supplied in a convenient and relatively small 360x220x65mm carry case made from tough and durable ABS plastic.
The carry case is held closed by a latch built into the case. The latch itself does not move and the case is opened by pushing the top and bottom halves of the case inwards slightly, twisting the case and clearing the latch. There are 'PUSH' signs on the edge of the case.
The Geoscope has a clever folding design in which the large outer mirrors rotate and slide inwards for packaging.
The large outer mirrors are unpacked by firstly sliding them outwards and then rotating them into position. The mirrors a packed by reversing this operation, rotating them and then sliding them inwards - note that the mirrors slide in independent slots at different heights.
The outer mirrors are held in position by the weight of the stereoscope and they rest on seats built into the body. The legs should rest on a flat surface to prevent the body twisting and causing misalignment of the mirrors. The design works well for its intended purpose of viewing prints on a flat surface. With some care it is possible lift the stereoscope and even tilt it to view a vertical monitor or print, however it was not designed for this and the mirrors will swing out of position unless held and the body is not rigid enough to maintain good alignment of the mirrors when not sitting on a flat surface, and also take care not to tilt the Geoscope with the eyepiece installed as it will fall off and may be damaged.
For a good field of view it is necessary for the eyes to be close to the first mirrors and the body has a room for your nose enabling the eyes to be very close. The Geoscope may be used without the eyepiece installed but the first mirrors are exposed and can become dirty from the touch of the face and the oil can be hard to clean off.
A 1.2x magnification eyepiece is included with the Geoscope Standard model. The eyepiece fits into four small holes in the stereoscope, and while this prevents the eyepiece sliding horizontally it is held in purely by its own weight and will fall out if the stereoscope is tilted. There appear to be other mounting holes and these may be designed for use with 3X binocular eyepiece included in the Geoscope Pro model. The optical path length is around 11.2 inches and the eyes need to focus in the distance with these lenses, and some people who are short sighted have had difficulty focusing with the lenses installed - if this occurs then it may be possible to us a foam board etc under the scope to raise the height of prints, or just try using the stereoscope without the lenses.
A parallax wedge is included along with instructions for using it. The back came with a protective plastic cover which although scratched is intended to be removed before use.