Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: how does the motion detect work? does it just automatically start recording when it detects a motion?
Document: i like the motion detect setting, it record clear not bad for the price. im happy with this product.it also have zoom in and out just great. the audio needs some work on, but over all great. the built in battery last for about 1 hour.
a nice and compact camera which is easy to start and easy to use . motion detection is really a good idea for that
I bought this product, and didn't recieve the right one. The Amazon guy said that there's no such a product. It didn't had the HDMI, very poor quality, complete chinese junk!!! for this product one star is too much! I'm very dissapointed with this junk. Sorry but this is true.Motion Detect Car Dash Video Camera Recorder DVR
This allows the camera to be used in the same was a a flip camera. Its small and light enough for use as a spy cam or on board of a model airplane. Plugged into the cigarette lighter adapter, the DV starts recording automatically when the car starts, and stops about 30 seconds after the ignition is cut. This is the desired behavior for a 'black box'.The included manual is terrible, as expected.
I received this "720P HD motion detect car dash video camera recorder 2.5 inch TFT LCD 1280x720, 30fps" as a birthday present about three weeks ago. By now I have tested all its operating modes, and I am completely dissatisfied. I do not recommend this DVR, because it cannot really provide useful evidence in the case of an accident.The resolution is totally unacceptable. Theoretically 720P should look crisp on a wide screen TV, but the video from this DVR looks terribly fuzzy on every screen.
Adjust the angle after viewing the test run so you get the best results.Still recommend this, but I am going to contact the seller to provide a longer cable if possible.3rd updateAfter using it for only 2 days, it shows a dead battery.It's not charing and the motion activation doesn't work.After my car is stopped and engine off, it continues to record for a full 15 min, every single time!!!
Recently purchased another car and decided that a car dash cam could come in handy. Researched many cameras even some well over $250. Decided that this camera would work for the basic essentials. Others camera could record when car was parked over night since it had motion control and other features. Felt that these features were not necessary for a extra $200.This camera does not come with instructions but its practically self explanatory. Purchased a 16gb sd card which records over 5 hrs with this camera.
Why put in PC Cam option if it does not work? @!Playback on the LCD screen is small, therefore if you are looking for fine details in your playback use a PC.Fast fwd and rewind not available during playback.Glare from sun or night recording is below par.Button placement is downright intrusive during operations.Firmware update for this device is badly needed.
The recording software in the unit is not compatible with windows 7 and it corrupted my desktops card reader programs and I had to reload them to get my card reader to work again.The operational instructions with the unit are vague at best and in some places, make no sense at all. The unit itself is a fine piece of electronic engineering if you have the time to figure out how to set it up and operate it. Of course, if you can read Russian, its probably allot easier
What's neat about it is that it comes on automatically when the car starts, and records convenient video segments. When you turn your car off, it writes the final segment to its SD card and shuts itself off automatically - you don't have to mess with it. Video segments are easy to retrieve from the SD card.
Answer: hi when you chose the motion detection , your camera will start recording as soon as there is a movement in front of the visual fields . and if you have two cameras (front and back) it will still work that way for both of them .