Sunday, October 16, 2011

NCC 2011: Time Lapse Photography

Postcard from the edge:  The above image from a time-lapse series demonstrates the utility of side-deck coamings for keeping water out of the boat;  as here, when heeling at 24 degrees and burying the bowsprit in 3' waves and large rollers.  Here, crossing from Core Sound into Pamlico Sound,  the crew was hiking out on the starboard coaming.  Our portable battery-powered Atwood pump handled slosh.

Experimental Photography

In the 2011 WaterTribe NC Challenge (NCC) we, SOS and DWSB, experimented with time-lapse photography aboard the Dawn Patrol.  We used a Bushnell trail camera mounted on the tiller aft of the transom.   The camera took about four photos per minute during our 27 hours in the NCC.  The camera produced good-quality color photos during the daylight hours.  At night its invisible near-infra-red (IR) flash produced monochrome photos.  The camera uses 8 lithium AA batteries.  Between shots, it efficiently preserves energy to provide a battery life of weeks or months  --up to 12 months depending on the settings.

The camera has a 2" LCD review screen and can be used as a handheld camera for snapshots or video.  Or, it can be configured to run night and day for many weeks recording time-lapse photos.  It can also be set to record time-lapse video segments with sound.  Hunters would usually not use the time-lapse feature (a.k.a. "field scan mode"); rather, they would use its motion-sensor which triggers a photo or video segment whenever game stroll into view.  It can do both simultaneously: interval shooting and motion-triggered shooting.  In fact the only way to disable the latter is to blind the sensor with electrical tape.

The Photos

The good news is the camera took 5900 photos during our 27 hours on the water in the NCC aboard the Dawn Patrol.  The bad news is the camera took 5900 photos for us to sort through for use in time-lapse videos, slide-shows, or individual stills.  After tossing out blurred frames, over/under exposed frames,  and x-rated frames (changing clothes), we have 4589.  Here are some examples...

daylight color image
(Neuse River)
Twilight color image
(daybreak on Core Sound)

Twilight monochrome with IR flash
(Clubfoot Creek)
Night time still with IR flash
(Harlowe Creek)
Night time action with IR flash
(SOS spot-lighting markers in Newport River)
Backlit by late afternoon sun
Image taken when tiller was in motion
(Core Sound)
The Camera Mount

The camera was mounted on the tiller via a c-clamp camera mount with tether cord for security.  Just aft of the camera is the tiller's socket for the stern navigation light.  We chose to mount the camera in this location for several reasons:  We hoped that the occasional off-center positions of the tiller would help counter the camera's limited field of vision (50 degrees)  --but we knew the tiller would almost always be pointed straight ahead.  We hoped that the camera would not snag the mizzen sheet.  Putting the camera aft of the stern light would have blocked the stern light. 

                       Camera mount                                                                                          Side View
 The Camera

The all-weather camera was designed to be mounted on a tree trunk to create a photo-trap for discovery of game animals (deer, turkey, etc.) or bigfoot or poachers.  Mounted for an overnight test on the Dawn Patrol in our driveway, it captured the expected images as well as  --what else--  deer grazing in the lawn.

Model  #119456
"Bushnell 8MP Trophy Cam Night Vision Color LCD Digital Trail Camera"

Left:  2" LCD screen and control buttons,  8 AA batteries.    Right:  the back has attachment points, 
while the the front has an LED Array, a sheltered lens, and a motion detection sensor 

Left:  SD card slot, USB port, audio port, AD power,  mic (array of tiny holes)
Right:  hole for AC power,  rubber plug for hole,  1/4" camera mount socket
The camera housing is a hinged box with an o-ring seal  --similar to a small Pelican case.  We sealed the array of tiny microphone holes with electrical tape.  From the inside we applied electrical tape to seal the AC port's large, rubber-plugged hole.   These appeared to be the only obvious paths of potential water infiltration.  The camera is rated to handle splashes (rain), ice, etc.   However,  it is not rated for submersion as might occur during a capsize of the sailboat.

Array of 32 IR LEDs,  plus 2 center LEDs
that signal the status of the camera.
List of camera features:  8 mp resolution


The camera worked well, about as expected,  in terms of the photos produced.  At night the IR flash was indeed invisible expect for a very faint red glow in the LED array  --which signaled to us when a photo was in progress.  The camera stayed dry and we did not capsize.

One disappointment:  the camera's clock was defective.  The correct date and time was stamped on each photo for the first 3741 photos, but then at 11:11pm the clock time-traveled to 08-10-2022 08:05am.   Then on the 3809th photo the clock jumped to the first minute of 01-01-2011.  After that the clock jumped on five other occasions to arbitrary times for no apparent reason.  Apart from these occasional episodes of time travel,  the camera continued to snap photos every 15 seconds, approximately, and kept accurate count of the time between frames.  Because of this clock defect we returned the camera for a refund.  We had no choice as having the wrong time stamps on the photos (and wrong creation dates on the JPG files)  was unacceptable.

Many thanks to that big NY camera store, B&H Photo,  for their outstanding customer service and free shipping in both directions.   I would buy from them again.

Lessons Learned

1.  A wider field of view would have been better!   We knew that,  and if time had allowed, we would have explored mounting a wider-angle lens on the camera before the NCC.  Several vendors sell such lens for use on iPhones and other cellphones.  (AGPtek)  

2.  A mount further aft might have been better.   This might not be necessary if a wider-angle lens is used. The camera could be mounted on a rigid boom 3' or 4' aft of the transom (not on the tiller).   The IR flash seemed too close to the cockpit.  In the night photos, we can see that the camera was too close to the mizzen sheets (ropes).  Occasionally, at night, one of the sheets moved in front of the lens and the IR LEDs flashed point-blank into the sheet causing washout of the entire photo.  When the mizzen sheets were slack they occasionally snagged on the camera.  On one such occasion at 3am the camera's aim was shifted to point at the cockpit sole and in the darkness we did not notice the shift until almost 6am.

3.  Comparison to video recording.   Waterproof compact cameras (here) and adventure video camera such as the GoPro HD Hero 960 can be submerged, have wide/wider angle lens, and are known to produce very good short segments of HD video.  For example, the Panasonic Lumix DMC-TS3 for snapshots and HD video has an 80 degree field of view.  And for example, the GoPro has a 170 degree field of view and records HD video (or time-lapse video) --but all subject to a battery life of about 2.5 hours.  How does recording a set of video segments compare to recording a set of start-to-finish time-lapse frames?   They both have their pros and cons, and their end results are complimentary.   For example, at the most exciting moments it may be difficult or impossible to activate/manage a video camera,  whereas the Bushnell camera never needed any attention.  On the other hand, when it is feasible to activate/manage the video camera the results can be great.  

What's Next?

We plan to post most of the time-lapse series.  We will break the series up into various segments of the NCC and present each subset of frames as a time-lapse video, a slide show, or as selected individual frames.

We would like to experiment further with a start-to-finish time-lapse camera (e.g. Bushnell) 
--if we can set it up with a wide-angle lens.

We would also like to experiment with an aft- boom- mounted video camera managed by a handheld remote control   --if we can find such a camera!  GoPro, are you listening?   (Probably not.)

And while we are dreaming,  a light-weight gimbaled camera mount would be a fine improvement. 

Alternatively we could just go on a nice coastal cruise in the company of another sailboat  ...perhaps one with a crew of professional photographers.  Now there's a new idea.