Shutter Speed And Fps

So it will send each images 3 times in a row, right?

It depends on the camera. If you are lucky it won't, it will just slow the frame rate to the shutter speed. Otherwise it would seem to waste space by having to store frames that add no new information.

How much space though is a good question, since, assuming one is using H.264, any duped 'P' frames would need to contain little more than the scene change information, which would be assumedly nothing, except possibly for overlay information. The cameras I checked all seem to throttle down the framerate, so I can't be sure what others might do.

On the surface, setting the SS to be slower than the FR seems to make little sense, though in practice it might occur when you are trying to capture a maximal frame rate (during the Day) and are allowing long exposures at night, and have no mechanism to reduce the framerate concurrently (dynamic profile).

Anyhow in practical scenario this 1/10 can cause motion blur so i need to use 1/30 s shutter speed to get 30 fps ,right? But consider low light scene where I am going to keep 1/20 s shutter speed and 30 fps,will it make that much impact?

I'm not sure exactly what you are asking. Will what make much impact on what?

Are you asking: With the nominal framerate set at 30, will 1/10 SS or 1/20 SS or 1/30 SS make much impact?

• On blur? If there is significant motion yes, how much depends on how fast the motion is.
• On the overall brightness or noise of the scene? Since it is allowing 50-100% more light on each exposure, yes, it will increase the overall luminance (or reduce noise thru AGC reduction)
• On the actual framerate? Again possibly, depending on how your particular camera handles SS slower than the framerate, see above.

Background: Training: Frame Rates for IP Cameras, Trend: Day/Night Profiles for IP Cameras