General Weather/Earth Sciences Topics > Weather Photography
Time Lapse Process and Techniques - Edited 2/7/18
GregJ:
Everybody that does time lapse has their own process and technique. I was asked to share mine. It is unique to my situation. I use the Sebectec Olympus SP500 package (excellent software). I have 3 cams aligned to form a panorama. We are fortunate to live in a location with a very wide view. It takes 3 cams to get it all in. Aligning them is a painful process, but final adjustments can be made with the Sebectec software. A separate computer is needed for each cam. I use 5 computers to run my site. http://www.skunkbayweather.com/
I run my cams 24/7 and take an image every 20 seconds and upload once a minute. Every day, each cam takes approximately 3,500 images. At the top of every hour, I have the Sebectec software configured to create a 1024 x 576 time lapse of the previous 3 hours at 30 frames per second and a bitrate of 24,000. These are the hourly production time lapses I put up to my site. I just put together this new page: http://www.skunkbayweather.com/SkunkBayWebcam.html I also put the same time lapse at 1280x720 up to a public folder for remote access and to share with the media. These are a little higher quality and too big for most internet connections to stream efficiently.
All of the above would be what I call production work. The Sebectec software is basically a set it and forget it package…. For the ad hoc work that I do, I use Movie Studio Platinum 14.0. It seems to meet my needs. I have some dynamic scripts that I can use to pull the images I want to use into specific folders…. For example, the script will pull all the images from 2:00pm to 8:00pm from each cam and drop them into my 3 working folders on my local machine. If I am going to “stitch” them into either a 2 or 3 cam panorama there is a bit more to it. The images really need to be aligned chronologically. In other words, the cams work at slightly different speeds. I built an Excel spreadsheet that analyzes the time stamps of all the images and creates a text file with a list of images to use in the time lapse. The strategy is to look at all 3 images and if one of the cams starts to fall behind, it will use the same image twice from the cameras that are getting ahead. This way I try to keep the images as close together as possible. You really can’t see the doubled up images. Sebectec can then use that image list to create a time lapse video. The three files will have exactly the same number of images. So, after I have created those 3 time lapses, I open them in Movie Studio. I put each file on its own video track. Then I adjust the offset to align each one side by side. In other words, the video from Cam1 is on the left. I adjust the X offset to -640, 0 (centered) on Cam2 and +640 on Cam3. All of the heights are adjusted to 360. This nets a 360x1920 video that is centered. It also is produced at the standard 30fps. Once I have that video, I can start enhancing it.
I believe the real value of time lapse is that it should tell a story. In order to present it in a way that allows our eyes to process the information, the playback speed needs to be adjusted. This will greatly enhance the story. For example, the Weather Workshop video I put together opens with a Superior Mirage time lapse. It is a full day in 1 minute. By speeding it up you can see the opposite shoreline and mountains jumping up and down very clearly. That tells a better story. In the middle of the video there is a sunrise that is gorgeous. I slowed that one down as much as I could without making it choppy. I wanted to give the eyes plenty of time to drink it in. Every time lapse in this 11 minute video has been chronologically edited to tell a better story. http://www.skunkbayweather.com/WeatherWorkshop2015.mp4 It’s all subjective. Adjusting the playback speed is quite easy. This is done simply by stretching or shrinking the time line in Movie Studio.
With 3 cams, I like to use a variety of angles to tell the story. I’ll use the 3 cam panorama to give the big picture and individual cams to show detail. Here is a big convergence zone that rolled through last week.
Big picture with the 3 and then details from each cam. There are a total of 6 time lapse video files involved to put this together. 3 chronologically aligned files for the panorama and then the three individual ones. Each one is edited for both playback speed and duration.
There are a couple of things that I think make difference. When you adjust the playback speed, it seems to smooth the video a bit. You can take it right to the edge of jerkiness and then dial it in. The other rule I try live by is that the average viewer of a time lapse will have an attention span of 20 seconds and if you are lucky you can hold them for 30. I try… to live by that, but it is hard sometimes.
So…. I have rambled long enough. Once I start typing…. I hope I have shared what you are looking for. It sounds way more complex than it is. After you do this a bit, it is pretty easy.
Greg
Bushman:
Thanks for the detail. Is it possible to run three virtual machines on one PC to process the pano? Seems like a waste to have to run three boxes.
GregJ:
The cams are run by USB, so there is no way to address each cam individually. It you put them all on one machine they get confused. These are older refurbed boxes that I get for $200....
Greg
Bushman:
I've used USB in a Virtualbox. http://www.dedoimedo.com/computers/virtualbox-usb.html Just sayin'
GregJ:
Thanks Bushman. I'll look into this. I did play with a version of VMware and it was unable to uniquely identify a USB port. The system needs a unique, dedicated access to each cam. I'll take a look at the link you provided.
Greg
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