With time lapse photography, something that is usually not visible by the human eye suddenly bursts into life and can be amazing to watch. The sequence is captured by taking a series of photographs a few seconds, minutes, hours or even days apart, they are then all joined together to form a series of images that appear as one film. There are plenty of things from the natural world that make great time lapse subject which include rotting fruit, the sun moving across the sky, clouds and plants or flowers growing, blossoming or even dying. You just need to pick one, do some simple maths, shoot your stills and join them together to make your film.
You can use compacts for time lapse photography but a DSLR is the best option as they give you more control. If you're using a DSLR borrow an intervalometer (if your camera doesn't have one built-in). It's a remote control which you can programme times into so you can go off and do your shopping while the camera snaps away. You can also get software that controls the camera when connected to a laptop but this isn't as convenient.
Making life even easier are cameras such as the Olympus OM-D E-M1
and Olympus PEN E-P5
as these have interval shooting and time lapse features actually built in.
You'll also need a tripod because unless you're particularly good at musical statues and can stand in one position for a very, very long time, you'll move the camera which means you'll end up with a jaunty final piece. If you don't have a tripod try using a table, beanbag or some other sturdy support that will stop the camera from moving.
If you're working away from home you also have to think how you're going to power your camera as batteries do run out and you'll need to be careful when changing them as any camera shake will spoil your image. You'll also need memory with plenty of space and if it's a particularly bright day a neutral density filter can be handy.
While deciding on your subject think about how much time you have to dedicate to this project. If you only have a day, go for something like a flower opening rather than a piece of fruit rotting or even a plant growing which can take days or even weeks. The length of time the transition of the object you're photographing takes and the interval you take the shots at will also change the appearance of the final image. For example, a piece of rotting fruit which may take three or four days to rot, you'd be OK taking shots with longer breaks in between but for something shorter such as a bud opening you'd need to take shots at shorter intervals otherwise your final film will look jerky. Also, remember that you could end up shooting for hours to only have a few minutes of footage so be patient!
There are several time lapse calculators
available online and as apps which can help you figure out the intervals, recording and playback times just by entering one of the values you already know which means you won't have to do any maths (which is always a bonus).
Don't forget to set your camera on a tripod and set the white balance manually as due to light changes, if you use auto white balance you'll end up with a collection of shots that are all balanced differently. For this reason you should use manual exposure, too and shoot in RAW.
When it comes to editing, you may want to tweak the images in Photoshop but you'll also need software to create your video in. There are plenty on the market all of which have various prices and range in complexity to use.