Selecting a camera
Making a movie

Introduction
The availability of digital cameras has made time-lapse movies relatively easy to make. For example, it is now possible to make decent time-lapse movies using the cameras that are part of ones computer, smartphone, or other device. Also, there are many digital still cameras available that work well for making time-lapse movies. However, because digital cameras are continuously being updated and replaced by new models, it is difficult to recommend specific makes and models. Rather than trying to recommend a particular camera, the information provided here may provide some of the basic features that make a camera suitable for making time-lapse movies.

Being a plant biologist, we use plants as our subject of choice but time-lapse imaging is also great for making movies of all sorts of other things, like the flow of people in public places or clouds drifting across the sky. In addition, many of the same techniques can be used to make stop-action movies.

Selecting a Camera – A critical step to time-lapse imaging is, of course, finding a camera with time-lapse capability. There are several things to consider before deciding on a particular camera. In general, it is probably best to look for the highest resolution camera and best lens system you are willing to pay for. Even if your immediate needs do not require high resolution images, once you get started there is a good chance you will want better resolution images after a while. As with still images, you can always downsize a high resolution movie but increasing the size of low resolution movie usually doesn't work very well. Indeed a numbe of the movies on this siter were made when the only affordable time-lapse we had were low resolution webcams. The movies taken then were very low resolution and the only way to imporove the movies now would require starting again.

Computer-controlled or free-standing camera? There are many more camera options when it comes to using computer-controlled systems. For example, many of the canon cameras, including their digital SLRs come with software that provides time-lapse capability. However, you may not be able to use the computer while it is controlling the camera. In addition, being tethered to a computer can limit the locations where you can set up your camera for extended periods of time.

If your demands for image quality and resolution are not high, some of the inexpensive web cams will do a good job but few of them come with software that allows time-lapse capture. Fortunately, there are a number of freeware or shareware programs available that provide time-lapse functionality for various web cams. Although the web cams typically have low quality lenses and limited resolution, they work well for some uses and they are inexpensive.

Free-standing cameras provide a great deal of flexibility in terms of where you can set up. Several of the Nikon cameras (Coolpix and DSLR's) have time-lapse capabilities built in and work great for capturing time-lapse sequences. Also, most other cameras can be attached to a simple intervalometer that will control the image capturing process for you.

Given the rate at which new cameras appear, selecting a camera that will work for your situation will require some research. To learn about the capabilities of many of the currently available digital-still cameras, you can try the following digital camera web sites:
http://www.dpreview.com/
http://www.steves-digicams.com/
http://www.imaging-resource.com/
The reviews on these sites sometimes fail to mention time-lapse functionality so you may also need to look at the manufactures specifications.

Making a movie – Before setting out to make a time-lapse movie, you should become familiar with your subject. For example, to make a movie of a particular plant, it is important to know how to grow the plant, how fast it grows, what stage of growth or response you want to capture. You chance of success will greatly improve with the more you know about the subject. For example, an understanding for the time required for the process of interest is important when making critical decisions the time interval to use between images. For example, if you want to film the opening of a particular flower, you need to determine when and how quickly flowers of that species open. In the case of morning glories, the flowers may open between 5:00 and 6:00 am and may be fully open by 8 am. To capture a movie of the opening process, intervals of 1 to 5 min should work. If you don’t want to get up at 5 am, you would need to set up your camera the night before. In some cases, using artificial lights can affect the way a plant or flower grows so some experimenting ma be required to achieve adequate results. Most of the movies on the Plants-In-Motion site required several attempts before we felt they were adequate for their intended purpose.

One strategy when working with a new plant is to set up a camera using 30 min intervals and let it capture a few days worth of growth. Upon examining the image series, it is usually possible to determine an appropriate time-interval needed to capture the process of interest. Shorter intervals will usually make for smoother playing movies but larger files.

Always try to use manual focus and exposure settings. Autofocus can get confused as the subject grows and changes, which could result in focusing on the wrong object. If you use fluorescent lights, you should use a shutter speed of 1/15 s or longer to avoid the 60 hertz flicker of the fluorescent bulbs. Make sure you use the correct white balance for the light conditions you are using. Like the autofocus and autoexposure options, auto white balance doesn't always work the way it should. You will need to experiment with your camera, subjects and conditions until you get results you like.

Building movies from still images – Some capture software and some cameras can automatically make movies as the images are captured. However, if your save the individual images in a sequence, you will have many more options for using them. QuickTime Pro ($30 registration of the free player will let you activate the Pro features) will take a folder of images and make a movie from them as long as the images are named in sequential numerical order. Most time-lapse capable cameras use the time and date to name the images so they are automatically sequentially numbered. Depending on how many images were captured and their file sizes, it usually only takes a few seconds to import them into a QuickTime movie. There are many other programs that will allow you to turn an image sequence into a movie, including the newer versions of Photoshop.