True orthostereoscopy is rarely achieved. It strictly means the image looks exactly like the original scene. For computer viewing it can only be achieved for objects not much further away than the monitor surface. The stereo base must equal the inter-ocular distance (taken as 65mm here), the image must be viewed from the same distance the camera was away from the object (450mm here) and the image size must equal the object size (80mm across the aneroid barometer). Clearly the image will not be orthostereoscopic if your monitor is too small (this is set up for a Samsung 22 inch monitor). It is impossible to free view a parallel stereo pair this big from 450mm and a stereoscope without magnifiers will be needed (e.g. Pokescope, ScreenScope). You will know you are seeing orthostereo when the squares look square and circles look like circles and the aneroid is 80mm transverse diameter.
You may observe the aneroid and squares are not distorted if you view from 450mm, no matter what the image size is. Distortion depends on the image distance and interocular distance during viewing, plus object distance and stereo base during photography. Orthostereoscopic means both free of distortion and correct size.