Archive for June, 2010
Another time lapse, this time of a trip I took yesterday. Created using a Canon A480 and CHDK.
Here is another time lapse of storms building over the Santa Catalina mountains. The black specks that keep appearing are birds going to and from our bird feeders.
It was generated with 3750 pictures taken two seconds apart using CHDK.
Here is another one – it’s a strange angle because I needed to keep the oven light out of direct view of the camera. Total time elapsed was 20 minutes. Compressed to 33 seconds. Generated using a Canon A480 and CHDK.
Last weekend we took a drive from Tucson to the top of Mount Bigelow, which is home to TV and radio antennas. Some stats:
- Driving time – 55 minutes
- Distance – 31 miles
- Altitude gain – 5,500 feet
- Temperature drop – 29 degrees Fahrenheit
- Pictures taken – 1,219
Some things to look for:
- Overexposure in most of the frames. This is because I forgot I left the camera on ISO 800. Don’t do that.
- 0:24 – cyclist
- 0:25 – end of the cactus, start of the small bushes
- 0:29 – fee station
- 0:41 – start of large trees
- 0:50 – Windy Point, a popular vista location to look down on Tucson
- 0:55 – start of the pine trees
- 1:06 – turn off the main road onto a dirt road
- 1:12 – Forest Service truck
- 1:13 – people camping
- 1:16 – a family with a dog
- 1:18 – looking north towards San Manuel, Ariz.
The Canon A480 doesn’t have manual focus of course, but by adding CHDK it does! At first the feature appears to be broken, so here is a short video demonstrating how it works. It’s called Subject Distance Override and to turn it on in record mode press Mode then up (ISO).
It’s amazing how Pinnacle Studio and it’s Dazzle interface can take a nice clean input and make it look like an old VHS tape…
A total of 105 exposures at 30 seconds each, ISO 400. Canon A480 running CHDK. No in-camera noise reduction. Four dark frames. It took just over an hour to take the pictures.
I think Google’s software engineers needs to work on their walking directions a bit more. I was playing around and decided to see the walking route from Watford, UK to Plymouth, UK. Here is the result:
Note the warning: “Use caution – This route may be missing sidewalks or pedestrian paths”. Oh yes…
CHDK is an alternative firmware for many Canon cameras, particularly point and shoot and I previously wrote about it here. One of the nice features is the ability to take continuous pictures for long periods, which makes taking photographs of the night sky possible with a low cost camera.
Here are my first experiments to see what is possible. I am fortunate to live in a place where the light pollution isn’t so bad and there are over 300 sunny days a year.
I set my Canon A480 up to take continuous 30 second exposures pointing roughly north, around 45 degrees above the horizon. I left it for about one and a half hours, during which time it took 155 pictures. I used ISO 80 and the auto focus set to infinity. More >
CHDK is an alternative firmware for some Canon cameras. It provides access to lots of cool features that are found only on high end SLR cameras, plus some features that are not found anywhere.
Why the Canon A480? Because refurbished cameras are available for $75 from Adorama with a one year warranty and only one version of firmware has been seen on them to date. This means that there is a very good chance the firmware in the A480 you receive will be compatible with CHDK.
This short guide shows how to quickly access some useful features. It is not intended to be exhaustive or replace the CHDK wiki or forums.
CHDK can be set to automatically load when the camera is turned on, however I don’t use that feature because I want to use an 8Gb SD memory card. Cards of 8Gb create complications when autoloading CHDK, but I want the extra space for long time lapse photography.
Recently I had the need to take a set of jpeg images and convert them into a high definition time lapse video, then upload to You Tube. Easier said than done…
To get the best quality I wanted to use H.264/MP4, which is also recommended by You Tube. I also wanted 1080P. The problem is that You Tube doesn’t seem to like B-frames in the file, and messes up the start of videos. So here is the solution I found.
Firstly I needed to upgrade my Debian server to Squeeze.
Next I compiled x264 and FFmpeg as described in How To Build FFmpeg on Debian Squeeze.
Finally I ran the following FFmpeg command line to generate a time lapse video at 24 frames per second (-r 24), using 1080P (-s hd1080) with no B-frames (-bf 0):
ffmpeg -r 24 -i %04d.jpg -s hd1080 -vcodec libx264 -vpre hq -bf 0 -crf 16 myfile.mp4
It’s important that the frame rate is specified before the input source in order to make FFmpeg apply the frame rate to the source. Note that trying to use qt-faststart causes You Tube to complain about the audio, even though there isn’t any audio.