Title: | Upper Valley of the Danube |
Date: | 1930s |
Material: | Photo paper on cardboard mount |
Company: | Keystone View Co. |
Location: | Meadville, Pennsylvania, USA |
A Keystone eye-training stereoview. The two images are identical so there is no sensation of depth. Used to illustrate by contrast the effect of stereo images. The Keystone Co. manufactured stereoviews for eye training until 1972.
