Thursday, 10 July 2014

Cambridge Timelapse

I've been meaning to have a go at timelapse photography for some time, but not willing to sacrifice my 5d mk2 to so many shutter actuations. Collecting dust on a shelf  I've got a 5d and a 400d both of which are about 7 years old now. The 400d has been used less than a dozen times and I should have really sold it on Ebay, but it's hardly worth it. It's a good little camera a bit fiddly to use and the viewfinder is positively tunnel like. Just over a year ago I saw a cheap intervoltmeter on Amazon compatible with the 400d and added it to my wish list. I often add stuff to my wish list I find interesting or for reference (I have since created a private wish for such things now). A few weeks later to my surprise my mother-in-law had bought it for me and it arrived in the post. Having read the instructions I did a few test shots then put it back in my computer cupboard to gather dust along with the cameras.

I'm notoriously impatient when it comes to photography and the idea of taking hundreds of photos to do a load of post processing on and convert into a video dampened my enthusiasm somewhat. 

Three weeks ago when my daughter was out punting with pathfinders (youth group from church) I decided to bite the bullet and give it a go. It was a disaster, for the following reasons:

  • A poorly framed photo will not make a good timelapse
  • You need lots of photos, 30, 40 or 50 is a complete waste of time.
  • Movement in the frame is good (it goes without saying) and setting the right interval is key
  • Landscape images only please! At one stage I found myself taking a portrait timelapse because that was more pleasing framing, 16x9 video for screen doesn't work in portrait!
  • Have a decent sized memory card, I was shooting Raw on an old 2gb card I had kicking around
  • Charge your battery properly (not 15 minutes before you leave!) and take spares
  • Switch everything to manual and switch off autofocus (this is one mistake I didn't make)

So after learning the hard way, I decided to do a little more planning, charged up my batteries broke out a few 4gb cards (i've now bought some 8's) and set off to the Lion Yard car park roof on a nice sunny day. First off I found that the nice puffy clouds were moving quite slowly, I opted for an 8 second interval, but in hindsight 10 seconds would have probably been a bit better. 33 minutes later and 250 RAW shots in the bag I hot footed it off to my next spot. Parkers Piece was covered in lots of activity setting up for the Big Weekend, not sure I wanted to capture all the railings and hoardings so I headed over closer to the Fire Station and started off another timelapse. I set the interval to 2 seconds since there were quite a few people walking around.

After amassing 500 photos from a very short period of time I had to decide how to process them. 

I downloaded the lot into Lightroom made some simple adjustments to the first image, copied develop settings then pasted these settings to the next 249 shots. Exported them as .jpg full res.

Lightroom interface

I now had my first batch of jpgs and needed to find some software to create a timelapse. After a bit of googeling I came across Panolapse  in the blurb it describes it's self as :

"Add motion to timelapse videos. Panolapse uses perspective correction to create real-world rotational panning through your scene. Also zoom, deflicker, blend RAW metadata, auto-exposure, create videos, and more."

Sounded promising so I downloaded the free copy which has a few of the bells and whistles turned off, but as a start was perfectly adequate. It's quite basic, easy to use and the video quality isn't half bad. At some stage I will certainly buy a copy so I can step up to full hd. Free version only allows output at 720p.

PanoLapse interface

After processing my first 250 shots at 24fps with deflicker switched on I opened up my video in media player and sat back for 10.4 seconds. Flipping birds every 2 or 3 seconds which just appeared as black dots on a single frame! Back to Lightroom and the spot healing brush, some time later all the birds had gone.....

After a few more lunchtime trips and a stack more photos I hit the next technical challenge, tripod movement! I was up on the top of Great St Mary's and the only place I could fit my tripod was on the benches you stand on to view over the railings. Half way through a time lapse sequence someone stood on the bench and shifted the image by a few pixels for a few shots then they stepped off. After some more googeling I came across Hugin and a command line tool which is bundled in with the distribution align_image_stack. Playing around with some settings and yet more googeling I managed to run the following command:

d:\align_image_stack -a out img_001.jpg img_002.jpg img_003.jpg img_004.jpg..........

To get the list of images I piped them into a text file and then edited this in excel, a bit of a faff, but it did the job. About an hour later I had a whole stack of out*.tif files. I've not found a way of using align_image_stack to output .jpg so I needed to batch convert these back to jpg for Panolapse to read them, I used FastStone Image Viewer for this.

Finally I was left with 8 Short timelapse movies, ranging between 150 & 300 shots each, now I needed to get them all joined together. Microsoft Movie maker is another free tool, easy to use after just a few minutes clicking on menu options.

Finally I was ready to upload my first timelapse to YouTube. I've still got a lot to learn, but I now have a set of tools I can work with when I take on my next timelapse project.

FastStone Image Viewer:

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