Sub-sensory imagery

The word "subsensory" means 'below the threshold of sensory perception.' Time lapse video recorded at 30 frames-per-second can contain sub-sensory imagery, such as the following examples from a recent time lapse of altostratus clouds captured on 17 December 2025 using my GoPro HERO4 Black action camera.

As you watch the video, can you see more than six jet airplanes that flew past the Sun? Probably not, but they're there! They're sub-sensory. I saw the airplanes when I used the left/right arrow keys to go back-and-forth through the video frame-by-frame; every plane is visible for several frames.

17 December 2025. Facing south-southwest.

Reagan National (DCA) is the airport nearest my home. My location is near the flight path of air traffic approaching and departing the airport, depending upon the wind direction. I saw more than six jet airplanes during the time I recorded the preceding time lapse video.

17 December 2025 | Elapsed time: 00:14

06. Jet airplane partially eclipses the Sun.

17 December 2025 | Elapsed time: 00:00 (less than 1 s)

01. Jet airplane plus large bird (lower-right corner).

I like the juxtaposition of a man-made bird and a natural bird in the preceding image. I saw the bird flying around in loops as the jet airplane moved from left-to-right across the sky. My good friend Mike Boatwright is a bird expert. Mike thinks the bird might be a Turkey Vulture.

Looks like a Turkey Vulture. They hold their wings uplifted like that and fly around in circles. Source Credit: Personal communication, Mike Boatwright.

17 December 2025 | Elapsed time: 00:02

02.

17 December 2025 | Elapsed time: 00:04

03.

17 December 2025 | Elapsed time: 00:08

04.

17 December 2025 | Elapsed time: 00:12

05.

The Backstory

The following iMovie features the first time lapse videos (two) I captured using my GoPro HERO4 Black action camera. The camera was set for "Video" mode / “Time Lapse Video” submode, using a resolution of 4K and an interval of one (1) second. The first video clip (00:28 s) is longer than the second clip (00:17).

27 April 2022. Facing east.

Notice the clouds are moving slowly from left-to-right across the screen; the jet airplanes are flying from right-to-left across the screen, since planes prefer to take off and land flying into the wind. Oh that's right -- you probably can't see the planes. Neither could I.

Post update: I watched the time lapse movie on a large screen monitor. Although I saw several planes in the sky (with my eyes) when I was outside, I don’t see them in the movie. That’s odd, because the camera was set to record every 1 s — more than long enough for a single plane to appear multiple times. Source Credit: GoPro Time Lapse Video: Richmond Highway (U.S. Route 1) - a blog post by Walter Sanford.

I saw the following sub-sensory images when I used the left/right arrow keys to go back-and-forth through the videos frame-by-frame.

In the shorter video segment, I saw a bird at 00:07, 00:10, and 00:11 seconds of elapsed time. A jet airplane is visible for several frames from 00:12 - 00:13 seconds of elapsed time. The images of the plane look hazy due to moisture in the air. Disclaimer: The elapsed times are for the original video clips. The equivalent times in my iMovie are different due to the addition of titles, transitions, etc.

27 April 2022 | Elapsed time: 00:12 - 00:13

01. Screenshot of a jet airplane.

27 April 2022 | Elapsed time: 00:12 - 00:13

02. Another screenshot of a jet airplane.

A large bird can be seen near the end of the longer video segment. Disclaimer: The elapsed time is for the original longer video clip. The equivalent time in my iMovie is different due to the addition of titles, transitions, etc.

27 April 2022 | Elapsed time: 00:26

Large bird.

Related Resources

• GoPro Time Lapse Video: Richmond Highway (U.S. Route 1) - a blog post by Walter Sanford
• GoPro: How to “Grab Photo” from Video - another blog post by Walter Sanford

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