Nathan's Occasional Blog

My wife Alicea and I just took one of the best vacations ever – 2 weeks on the Disney Wonder cruise ship from Miami to LA via the Panama Canal, with stops at Disney’s Castaway Cay in the Bahamas, Cartagena, Puerto Vallarta, and Cabo San Lucas.  HIGHLY recommended if you get the chance!

The focus of the cruise was of course the transit of the Panama Canal from the Atlantic/Caribbean side to the Pacific.  We made the crossing on Sunday, May 12, 2013 and I rigged up a camera on our balcony to capture the event.  Check it out!

I’ve had a few folks ask how I did this, so here’s the rundown…

Hardware

• Microsoft LifeCam Studio – I was hoping to take 1080p quality pictures, but ended up taking 720p pics due to processing power on the laptop I was using (more about that below); the biggest benefit of this camera over the LifeCam Cinema is it has a tripod mount receiver to screw it to a stand
• Joby GorillaPod GP3 – flexible tripod that’s sized for our Nikon DSLR (way overkill for a webcam, but I didn’t want to buy a single-use device)
• Joby BH1 Ball Head w/ Bubble Level for GP3 – allows you to adjust the angle of the camera independently from the flexible tripod, which is critical for fine-tuning the picture direction and level without compromising the security of the legs gripping the railing
• USB 2.0 extension cable – I knew I didn’t want my laptop exposed to the elements, so I got a long cable to snake through the door to our veranda.
• Lenovo ThinkPad X1 Carbon Touch Ultrabook – I was originally hoping to run the camera from my Microsoft Surface RT, but the LifeCam Studio isn’t supported on the Windows RT platform. So I brought my work laptop: Intel Core i5-3427U 1.8GHz, 4GB RAM, 180GB SSD
• Disney Wonder – DCL’s second “Magic-Class” ship: 11 decks, 965 feet long, 106 feet wide, 83,338 gross tons, 5 main engines producing 78,000 horse power, max speed 23 knots (26.5 mph), launched in 1999
• Panama Canal – infrastructure used to allow ships to pass between the Atlantic and Pacific oceans without going around the southern tip of South America (saves ~8000 miles of travel); ~48 miles long channel (ocean to ocean), 3 locks up – 3 locks down, 85 feet above sea level

Software

• Webcam Timelapse from TNL Enterprises – free app that can both capture the pictures from the camera over time and compile them into an AVI video file
• Windows Movie Maker from Microsoft – free app part of the Essentials Suite used to add music and onscreen text to the video

Concept and Testing

There are effectively two levers you can “pull” for a time lapse video: picture capture rate and the final video’s frame rate.  The capture rate is probably the one you will want to play with the most (see discussion below).  I left the video frame rate at the Webcam Timelapse default of 15 frames/second.  It’s ever so slightly more choppy than Hollywood movies (24 fps), TV broadcasts (30 fps), or your computer screen (60 fps or better for gaming), but with time lapse video everything is choppy so I don’t think it matters.

The length of your movie is just math:
duration of event (minutes) / captures per minute = total number of frames
total number of frames / frames per second = seconds of video

So if you take 4 hours of an event and take a picture every 10 seconds, then render a video at 15 frames per second, your final movie will be 1 min 36 sec long.
4 hrs = 240 mins
captures per min = 6    (60 seconds in a minute / 10)
240 min * 6 cpm = 1,440 pictures
1,440 frames / 15 fps = 96 seconds of video

The biggest point of advice I can make is to do some test videos before you try to capture your big event.  Make sure your webcam drivers are installed and your app can see/use the device.  Figure out how big each picture will be and ensure you have enough hard drive space to save them all.  Make sure you have line power or enough battery to last the full event you want to capture and make sure you have a way to disable any sleep timers your computer or OS may have.

For your test videos, play with the frame capture rates (how many seconds between pictures) to get something that’s both smooth and not too slow.  If you’re watching flowers open taking a picture every second is too fast, but if you’re shooting boats moving in a harbor capturing a frame every minute is likely way too slow.  There’s also the frame rate you use for the playback of all those shots to factor in to how fast people will see time pass in your movie (and how long it is).

I hooked everything up at home before we even left Seattle to make sure the apps and drivers were all in order.  I discovered then that I couldn’t run the webcam at full resolution because it kept grabbing lots of garbled or black frames.  The specs for the camera say you’ve got to have a quad-core processor to do 1080p video and my laptop is a dual-core, but I thought I’d be okay since I was taking stills.  I’m not sure if it’s the time lapse software, drivers, or combination, but the 1080p was not working well.  Perhaps the camera is slower to initialize 1080p and ever picture captured is a fresh “initialization” since I’m taking stills and not video??? Either way, the 720p setting looked just fine and in the spirit of not freaking out during vacations I just rolled with the punches.

We had a port of call in Cartagena, Columbia (beautiful city by the way) a couple days before the Canal crossing and a cargo ship pulled in next to our berth so I decided to set up the camera right and play around.  I’m glad I did since for that video I captured a frame every 15 seconds, which turned out to be a bit too coarse as I evaluated the output.  I tweaked the capture settings down to every 5 seconds and that looked perfect – that’s what I used through the Canal.  You can see this test video below.  15 seconds was great for some stuff (clouds, the big cranes moving along the wharf, the incredibly slow opening of the cargo doors opening on the ship), but it largely missed the tugboat going in and out a few times. The last ~2 seconds of this movie are fames every 5 seconds, and you can noticeably see the motion get smoother.

That’s actually an interesting point with the rig and method I used here – I can’t change between time-lapse and real-time in the final movie unless I sit with the computer and tweak the capture rate on the fly.  Ideally I’d love to capture everything in real time and then speed it up for large swaths of time.  That would have let me have more time to annotate some things onscreen in the Canal video (like the Chagres river followed quickly by Noriega’s prison), or use real time video at the start/end of the video.  But hey, I did all this for <$150 in hardware and free software; you get what you pay for!

My Setup

I set up my camera the night before we started our Panama Canal crossing to make sure I could get the sight line and horizon adjusted properly with daylight (we started the crossing before sunup) and to make sure the camera was acclimated to the outside conditions.  If you haven’t cruised in warmer climates before you don’t know the “joy” of waiting 20 minutes for your camera lens to acclimate to the high heat and humidity of outside from your cool and dry inside stateroom (it instantly fogs up).  Here’s an attempt to take a picture of a tugboat at the entrance of the Canal with our DSLR before the lens had acclimated.

Our stateroom on The Wonder was 8080 – nice and high on the port (left) side towards the back.  It’s also a 1br Concierge Suite that we scored as an upgrade when we checked in, but that’s a different story.  The nice thing for our purposes was that it has a double-veranda (essentially it’s two rooms side by side) so we had plenty of room to hang out on the deck and take pictures with our regular camera and stay out of the way of our time lapse rig.

As you can see, I used the Joby GorillaPod to get a nice and secure hold on the railing and then leveraged both the Ball Head and the webcam’s own “foot” to adjust the picture angle.  I actually wish the webcam’s foot wasn’t adjustable – it would have been easier to just tweak the ball joint and not accidentally move the camera itself; it took me quite a few tries to get the horizon fairly flat (and it’s still just slightly off).  If I had to do it all over again I’d want to find some sort of extension pole that would have allowed me to get a bit more out over the railing to maybe see down to the water line (there’s only 2 feet of clearance on either side of the ship in the locks!).

I knew from my testing in Cartagena that I wanted to use 5 frames per second max quality; the Webcam Timelapse app has some sliders for compression and image quality – I just maxed everything out.  I got the software settings dialed in, put my laptop to sleep, and set my alarm for 5:00a (the captain said that was about the time we’d be hauling up the anchor and heading towards the first lock).  As soon as my alarm went off all I had to do was power up my laptop, run the USB cable outside, plug in the webcam, and click the “start capture” button.  If you do this make sure you carefully route the USB cable through the door jam to optimize getting as best a seal as possible to keep the cold air in and hot air out at the same time you don’t break your USB cable.  The Disney ships use sliding doors so it was pretty easy to do if you let the cable hang vertically as you close the door.

The Webcam Timelapse app has a nice video monitor window that opens during capture so I could validate what the camera was seeing.  Note: it’s not super obvious, but you can resize that window.  After everything was up and running I took our DSLR and went up on the top deck to take pictures of the locks, etc.  Alicea went back to sleep.    The app ran all day without a hitch and captured 8,431 frames from 5:09a through 5:03p, or about 3.6GB (350KB to 550KB per picture).

Before I did anything else I made a complete copy of the frame capture folder and marked it as read-only.  Call me paranoid.  Then, with the Webcam Timelapse app still open, I ran through the convert to video flow.  It only writes .AVI files; there’s another quality slider (again, full up) and a frame rate selector (15 fps is default).  Please note this app doesn’t prompt you if you use the same file name as an existing file – use extreme caution and make sure you don’t overwrite a video file!  It took about 20 minutes for my laptop to render the movie, but when it was done I had a 3.77GB AVI file.  I dumped that on a USB stick and brought it and my Surface to dinner to show off – big hit!

Once we got home from the cruise I created a project in Windows Movie Maker and imported the AVI file in along with a couple tracks from MUTEMATH (awesome band by the way, if you’ve never heard them).  I also annotated the video with onscreen text with content sourced from our fantastic onboard lectures during the cruise by Capt Ken Pucket, a docent/narrator who came onboard with the pilot and spoke through the day on the PA system on deck, and a few reference tidbits from Wikipedia.  The final movie was bounced down in .MP4 format (693MB) and uploaded to YouTube (where I finally learned how to unblock a movie that has licensed songs in it – though unfortunately Warner Brothers blocks mobile devices from accessing the video as a result … whatever).

Summary

I think that’s about it.  This project actually got me pretty interested in doing more time lapse movies.  I too another one on the cruise of a sunset as we sailed from Puerto Vallarta to Cabo San Lucas, but the auto-adjust features on the webcam software kind of killed a lot of the colors there.  It’s still pretty cool though – check it out!

We’ve got an older Nikon D40X DSLR that I want to see if I can can run directly from a computer so I can better control color, focus, etc.  We’ve got a great view of Mt. Si from our bedroom and some beautiful sunsets from time to time – looking forward to experimenting!

Let me know if you have any questions or suggestions in the comments.

Final Stats

Panama Canal Transit video:

• 8431 frames (3.59GB)
• raw video length: 9:22 (3.77GB)
• edited video length: 9:59 (693MB for YouTube 720p MP4, 1.6GB for 1080p)

Panama Canal traversal:

• 04:53 – anchor aweigh (up)
• 05:09 – video capture started
• 06:10 – vessel entering Gatun Locks
• 07:45 – vessel leaves Gatun Locks
• 08:31 – let go anchor (we were “holding” for traffic to clear the Pacific side of the canal)
• 09:38 – anchor aweigh, continue crossing
• 13:53 – vessel entering Pedro Miguel Lock
• 14:38 – vessel leaves Pedro Miguel Lock
• 14:51 – vessel entering Miraflores Locks
• 15:51 – vessel leaves Miraflores Locks
• 16:55 – start of sea voyage (pilot departs the ship)
• 17:03 – passed sea bouy marking end of channel (video capture stopped)

Cruise details:

• Fuel oil consumed: 444,300 gallons (main engines)
• Diesel oil consumed: 1,663 gallons (generators during shore days)
• Fresh water consumed: 3,127,608 (created by onboard desalinization plant)
• Total nautical miles: 4,479
• Departure: 6 May 2013 16:58 – Miami, FL, USA
• Day 1: Disney’s Castaway Cay, The Bahamas
• Day 2: at sea
• Day 3: at sea
• Day 4: Cartagena, Columbia
• Day 5: at sea
• Day 6: Panama Canal crossing
• Day 7: at sea
• Day 8: at sea
• Day 9: at sea
• Day 10: at sea
• Day 11: Puerto Vallarta, Mexico
• Day 12: Cabo San Lucas, Mexico
• Day 13: at sea
• Day 14/Arrival: 20 May 2013 06:15 – Los Angeles, CA, USA