Some audio/video monitors filter out "normal" sounds and motions. The receiver is supposed to turn on only when your baby makes an unusual motion or sound, such as crying or rolling over when he's waking up from a nap. This feature is designed to extend battery life, although the receiver should be docked for overnight monitoring to keep the battery charged. We haven't tested any models with this feature, so we don't know how well it works.
The Infant Optics’s range within our test houses was never an issue, and, as with others we tested, we had to walk outside and down the street before losing the signal. The image quality was good enough to make out facial details 6 feet away in a completely dark room (as it was on others we tested). It’s easy to add more cameras to the set (you can use up to four Infant Optics add-on cameras, which are separate purchases, usually for about $100). You can mount the camera on a wall easily, pan and tilt 270 and 120 degrees respectively, and you can set the parent unit to scan between multiple cameras to keep an eye or ear on everybody at once—another nice feature that’s not unique to this model.
Video quality is a metric these products should perform well in, but most of them failed to offer a true to life image even in the daytime. It is disappointing that most dedicated video products aren't doing more than providing a blurry image of the baby in the room, and fail to show the baby's features or what the human eye would see in the room. The night vision is even worse than their day vision video, with some images being so blurry and hard to decipher that parents may end up going to baby's room simply because their baby has no face.
Baby monitors shouldn't be used as a substitute for adult supervision. They should be considered as an extra set of ears—and, in some cases, eyes—that help parents and caregivers keep tabs on sleeping babies. Using one can alert you to a situation before it becomes serious, for example, if your baby is coughing, crying, or making some other sign of distress. Experts warn that you can't rely on a monitor to prevent Sudden Infant Death Syndrome (SIDS).
The Nanit couldn’t be more perfect for analytical types. The camera—when placed just so—uses computer vision to watch your baby’s every move, and then tell you what it means. You get a notice on your phone, which acts like a handheld monitor, when your child is awake, acting fussy or has fallen asleep. The Nanit also assigns a sleep score to each night based on how many hours your child was actually crashed out. Other stats include how many times you went into your child’s room and how long it took for your little one to fall asleep. Because the Nanit streams live video and audio to your phone, you can also check in on your kiddo when you’re away from home. It also has a nightlight and temperature and humidity sensors.
This monitor is known for its zoom lens, included in the box, that lets you see your baby up close even if you have to position it farther away from the crib. You can use the monitor to remotely adjust the camera, and you don’t have to worry about plugging the monitor in overnight—it can sit on your nightstand for up to 10 hours in the power-saving mode (similar to sleep mode on your computer, but it still provides sound monitoring while the display is off) and up to six hours with the display screen constantly on.