Thursday, 30 June 2011

Making time lapse animations

Step one is acquiring the images.
Easy: many webcam software have automatic picture scheduling. In Webcam Zone Trigger, you need to go to the Video Settings tab, then click on the Camera Timer button.

Images will be round up in the save folder, and from there you can just select everything and drop them in a photo editing software. I use Gimp, which is free. In Gimp, Drag & Dropping a bunch of pictures will automatically distribute them on separate layers. You can then crop and resize the whole thing, and save them to the .gif format. You may be prompted to either flatten the layers to a single image, or produce an animation using each layer as a frame, choose animation.

Simple eh? :-)

Friday, 10 June 2011

Catching Lightning

Capturing images of lightning: not be super useful for everyday life, but it's hella cool.

The weather man lied to me a few times last week, to my great despair, no thunderstorm had struck. But last evening I heard the loud pounding of the incoming lightning, so I ran to my office and setup a webcam to catch a few snapshots of the bolts.

This requires a very simple setup. Just a webcam and a motion detection software (as always, Webcam Zone Trigger). Put a motion detection hot spot in the sky, large enough to cover a significant area, but no need to ever-do it. when lighting hits, the whole sky is affected. When the storm was done, I had 3 kinds of pictures:

Cloud-to-ground. Mostly what you would expect.

Shiny clouds
Cloud-to-cloud lightning, quite common, not as spectacular.

Split images
An amusing artefact from the webcam.
Lighting strikes fast enough that the scene changes while
the webcam's sensor is acquiring an image.

When you compare image quality between a webcam and a reflex camera, webcams tend to lose pretty hard. Not as sharp, not as high resolution, not as fast, and a much lower range of colors. But this all balances because digital cameras can't do the same things as a webcam. If you wish to take pictures of lighting with a camera, you'll need to do set a long shutter time, release the shutter and gamble that you'll catch a bolt within the time it remains open. Then do it again, many times. With a webcam, setup the motion detection and enjoy the show, pictures guaranteed.

Likely you'll keep the webcam indoors since they are usually not waterproof, make sure it is set in a dark room with no reflections on the window. Don't forget that most webcams have an on-board light that can reflect in the window.

Next time there is a thunder storm, become a fulminologist and snap a few shots.