Old Sketch Stereo

There are methods of semi-automating the addition of synthetic depth information into pairs like this. This one is based on 'flats' that have been laterally shifted, what I call 'cut shift'n'paste' stereo, although with photos it's not quite that simple [e.g. !] There are other methods involving 'horizontal only' 'spherize' filtering in Photoshop [ demo using a single stock photo from fellow dA member  . Here is an entirely 'synthetic stereoscopy' derived scene based on two copies of the same picture ! Further elaboration produced this . Synthetic stereoscopic collage is also possible, e.g. , as is 'symmetrical stereoscopic pair' formation using ordinary stereo stock, e.g. Floating Heart Shaped Autumn Leaves by aegiandyad . These processes are not secret.