In my research on hardware for VR video, I throw around the words “stereoscopic” or “stereograph” around. In a collaborator’s talk, I noticed that they referred to videos as “stereographic video” in a context where I would have used “stereoscopic video”, and was curious if there was a precise distinction.
(Note: I have never studied Latin or Greek, but if you have, the contents of this post may be boring.)
According to Wikipedia:
Stereoscopy (also called stereoscopics, or stereo imaging) is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word stereoscopy derives from Greek στερεός (stereos), meaning ‘firm, solid’, and σκοπέω (skopeō), meaning ‘to look, to see’. Any stereoscopic image is called a stereogram. Originally, stereogram referred to a pair of stereo images which could be viewed using a stereoscope.
So it seems to me, that stereoscopic refers to something that can visualize the “depth illusion” image (i.e. a VR viewer or headset), whereas a stereogram is used to refer to the depth illusion image itself. For your reference, the Wikipedia page on Stereography redirects to that page, as well. But a stereogram is not “stereographic video”, yet, so let’s continue our investigation to etymology.
According to the English Language and Usage Stack Exchange:
Q: What’s the difference between the suffixes -gram and -graph? Is there any difference? Even if they are completely synonymous, what’s the difference in etymology?
A: These mean exactly the same thing, except when they don’t. :)
[snip]
BTW, the etymologies are different:
-graph[French -graphe, from Late Latin -graphus, from Greek -graphos, from graphein, to write; see gerbh- in Indo-European roots.]
-gram [Greek -gramma, from gramma, letter; see gerbh- in Indo-European roots. Sense 2, from telegram.]
If you read the full linked answer, the accepted answer points out that for some words, the ____gram and ____graph words mean the same thing, and for some words the two mean different things, but that the etymologies are different. They point out that pictographs and pictograms are the same, but epigraphs and epigrams are not. I think it is safe to say that stereographs and stereograms are similar, considering people are not precise about these definitions at all!
Applying that paragraph’s assertion to the previous relation, a stereogram or stereograph refers to the depth illusion image. So stereographic video is just that, video that you consume in a stereo format.
That relation allows us to tie all these pieces together:
- a stereoscopic video is one that is captured from some sort of stereoscope or stereo camera.
- a stereographic video is one that can be viewed as a stereographic or stereo video.
Often these are the same, but not always, so I will take heed to write accordingly!