There is no reason why everyone should see stereoscopic 3D in the same way.
Originally Posted by Don Landis
Jeff- if I didn't step through the video frame at a time looking at the side by side I would not have detected the blu jay one frame behind every so often as it made its quick move and then remained still. The continuous movement of the leaves one frame out does give a blur as you said, the look of the watery flow. But, it was also out of focus because of the narrow depth of field.
The background of the video did not particularly trouble me. The movement of the birds and squirrels did - enormously!
At the 1m40s point, with a cut to a different point in time, I could immediately see an improvement, and relax. [The first time through I didn't even reach the 1m40s point; I felt so uncomfortable I stopped watching.]
I think this is a very significant finding: a timing discrepancy at the start of that video which for Wolfgang and me was practically unwatchable, but which was not distracting for you and your wife.
CREATING A TEST FILE
This may be an unnecessarily complicated approach but it is an experiment I did last year.
Here is an AviSynth script I loaded into VirtualDub:
Expansionfactor=1 # Use if source is full width side by side
Expansionfactor=2 # Use if source is half-width side by side
Quality=2 # For full width source at full quality, or to retain vert resolution with half-width source
Quality=1 # Normal quality setting, for much faster processing
# In next line, set whole number percentage of image width you wish to retain (minimum 50)
v1=selectevery(v,2,0,0,1,1) # selects frames 0, 0, 1, 1 of file v1 and then increments by 2
v2=selectevery(copyv,2,0,1,1,2) #selects frames 0, 1, 1, 2 of file copyv and then increments by 2
The above script duplicated the frames of a 24fps side-by-side 3D file to create a 48fps side-by-side file but misaligned the Left and Right content by the equivalent of half a frame at 24fps. [The addition of the thin slate gray border was to facilitate cross-eyed viewing.]
The content "==", and its misalignment, can be represented like this:
I redefined the frame rate as 50fps and saved the file. I viewed it on a 2D TV at 50fps, using cross-eyed viewing. It was of unwatchable quality for my eyes.
Tonight, I loaded up the file and played it on my passive 3D TV. It was so poor as to be of unwatchable quality. The Left - Right phase difference of 1/50th sec, for an underlying effective progressive frame duration of 1/25th second, was too much for my vision to accommodate.
I'll see whether I can come up with a method that introduces a smaller discrepancy. For example, from a high speed side-by side source selecting frames 1, 5, 9, 13, etc for Left; and frames 2, 6, 10, 14, etc, for Right.