What kind of camera should I get?

Your overall experience will vary significantly depending on your camera. First, there are two general categories of cameras: USB webcams, and network (IP) cameras.

USB webcams

USB webcams plug into the USB port of your computer (or you might have one built in to your laptop or monitor).

Pros:

Inexpensive (starting around $20 at any computer store).
Very easy to set up (just install the software and plug them into a USB port).
Small and light enough to mount in odd places.
Don't need to worry about network bandwidth or processing power of your computer (unless you want to hook up multiple cameras).

Cons:

Must be physically connected to your computer by a cable, though you can also get a 10-foot USB extension cable for about $10.
Many are optimized for video chat, so the software may not automatically adjust to, or work well in, very bright or dim outdoor lighting.

Who should get USB webcams:

If you want minimum hassle and just want one camera to monitor a simple scene (e.g., you just want to make sure people aren't coming into the room with your computer), a USB webcam might be your best bet.

What to look for:

Image quality. How optimized for indoor use is the camera? If you are only using your camera indoors, this doesn't matter. But if you want to point it outside, it's important that the image does not get washed out in sunlight or turn black at dusk. There isn't a simple spec you can use to verify this; if possible try to see what an image looks like if you point it outside. See "My webcam video is washed out." Logitech C500 and C600 webcams tend to perform well with a broad range of lighting.
Setup. How easy will it be to mount where you want it? Some webcams have clips, swivels and other design features for easy mounting on monitors for video chat. These can allow you to clip a webcam on to a lamp or set on a windowsill.
Resolution. Some webcams support megapixel resolution, if that is important to you.
Auto-focus. Designed to focus in on your face for video chat, this feature may actually decrease accuracy of recognition. The reason is that by making focus on some objects sharper as they move, the feature can make the software think there is more movement in the scene than there actually is.
Supported operating systems. Not all USB webcams have drivers that work on Mac OS computers.

Network cameras

Network cameras, or IP cameras, plug into computer networks and send video through the network.

Pros:

They can connect wirelessly to a Wi-Fi network, as long as a power source and strong Wi-Fi signal is available.
Higher quality and optimized for a broader range of lighting conditions.

Cons:

Higher cost, starting around $200.
Setup requires connecting them to your network, similar to the way that you set up a network printer. Sighthound Video has a camera setup assistant that can make it easier to set up cameras that support a feature called Universal Plug and Play (UPnP) and for Onvif compliant cameras.

Who should get network cameras:

If you are relatively comfortable poking around your Wi-Fi network (or know someone who is), and need a more powerful system, you might be better off with a network camera. For example, if you want to have multiple cameras throughout your house, are monitoring a darker scene outside, want more flexible remote viewing options, or simply want higher quality video, a network camera might be best.

What to look for:

Cost. Entry-level network cameras can be purchased for under $100. High-quality cameras start around $200. Additional cost depends on what features you want.
Video quality. The quality of the video source can have a noticeable impact on recognition accuracy. Axis and Panasonic cameras provide the best video quality we've seen in the $200-300 price range. Some cameras generate a large amount of "noise" in very dark scenes, which Sighthound Video may pick up as moving objects. As a result, we do not recommend monitoring scenes at night unless they are well lit, but this is a factor to keep in mind.
Network reliability. Check camera reviews or support forums to find cameras that drop network connections. Axis cameras tend to be relatively stable on wireless networks.
Wired vs. wireless (some models offer either as options). If possible, connecting cameras with wired network cables tends to be more reliable than connecting them through wireless networks.
Indoor/ outdoor. Outdoor cameras need to have stronger housings to protect cameras from the elements. As a result, they are typically more in the $500+ range. Panasonic BL-C140 (which can be found for under $200) and BL-C160 (under $300) cameras provide good but affordable outdoor camera options. The outdoor cameras tend to have rugged metal housings that attenuate wireless signals, and in general people don't tend to have wireless networks which extend outside building with a robust signal, so manufacturers don't usually optimize outdoor cameras for wireless configuration. Instead, they typically use a feature called Power Over Ethernet (POE), which means a network cable that also provides power.
H264 Streams. Incoming video from cameras that are not H264 must be decoded and will significantly increase the resource usage.
Day/ night mode. Some cameras are optimized to work in daylight scenes, and others have different degrees of support for night video.
- Axis cameras have software that adjusts camera settings such as exposure when it gets darker, but needs some amount of light to record.
- Infrared (IR) cameras. Some cameras illuminate scenes with infrared light for recognition in dark scenes. You can see an example of what video taken by these cameras looks like at the end of this video tutorial.
Resolution. Entry-level cameras typically record up to 640 x 480 (VGA) resolution. Higher end cameras go to 1280 x 1024 or higher.
PTZ capability. Higher-end cameras offer pan-tilt-zoom functionality (PTZ). This refers to remote directional and zoom control of the camera. Sighthound Video is designed to work with "fixed" cameras. When the camera is moving, stationary background objects will tend to be interpreted as moving objects. Once the camera stops moving, however, recognition will function normally.