Watching a 3D documentary: how to tell the difference between good 3D and bad 3D

It’s easy to tell when a 3D viewing experience goes sideways – sore eyes, headaches and a general feeling of awkwardness are unmistakable indicators.

Obviously we want to avoid these issues with our 3D content. And to fully understand how to do it right, you’ve got to understand how it’s being done wrong.

So what makes bad 3D so bad?

Digital Cinema Report has posted  an in-depth article on “How to Critique 3D” on how to identify the good, the bad and the ugly:

How to critique stereo capture 3D

-Your eyes should focus easily and naturally when viewing in stereo. If you are getting headaches or your eyes cannot focus, improper alignment is the cause (DCR tip: Take off your glasses and try to spot an area of high contrast. You may see that a bright spot is a little higher for one eye than the other.)

-When items on screen are glowing or have an unnatural sheen it is due to exposure differences between the two cameras. It could be unmatched exposure or reflection issues with the beam splitter rig.

-Keep an eye open for bright objects. Glints, lens flares and spotlights create more technical issues that have to be considered during stereo capture. Glints off of metal objects can be messy and appear to be a different shape in each eye. Lens flares will “invert” and pull away from the viewer, which can be visually confusing. Spotlights can create star patterns that rotate differently in each eye making it uncomfortable to view.

-Try to determine if there is too much depth onscreen. Some say it is perfectly acceptable for backgrounds to be out of focus. Others maintain that if the viewer cannot easy focus on distant objects there is too much divergence. (DCR tip: Look for distant objects like mountains or spotlights; If the doubled-image of the mountain appears separated by many inches or feet the background is probably too far away.)

Watching anaglyphic 3D

When we attempted to post a 3D clip from the Panasonic 3DA1 camera on YouTube, it was so everyone could judge the quality for themselves … ideally by being able to view the footage in stereoscopic 3D.

But if you can only view the material in anaglyphic 3D and 2D, all is not lost – use the anaglyphic 3D mode to analyze depth and the 2D mode to analyze footage quality.

Last but not least

If one of your 3D glasses lenses looks smudged it’s likely that the focus, zoom or shutters were not properly synced during filming.

Or maybe it’s just popcorn butter.

Ian Herring, President