frame rate

[boily 0]

if i purchase a dvr that is 8 channels and 200 fps @ cif which would give me 25 fps each channel would that be good enough to make a facial recognition of the person within 25m (camera 540tvl)

 

thanks

[Lesst 0]

Your Lens mm? = field of view and size of sensor? determines

[boily 0]

the camera 1/3 sony super HAD 4-9mm

[Soundy 1]

Framerate has nothing to do with facial recognition - all a higher rate does is give you more individual shots to choose from, it won't make them any clearer. 4CIF will give you four times the resolution and far better detail than CIF; 5fps@4CIF is better than 30fps@CIF if you're concerned with seeing details.

[boily 0]

whats a good 4 cif dvr brand model number

 

thanks

[Soundy 1]

Before you go tossing money at the wrong piece of the puzzle, what is this for? What is your budget? What is your existing equipment? If facial recognition is your prime concern, and you're not already locked into a particular camera, have you considered megapixel cameras? You can then use onboard storage (with some of them), or storage directly to NAS (with some), no DVR required. Even at the lower end of the market, 1.2MP is four times the resolution of 4CIF/D1.

 

1/3" chip, at 25m, you'd need a 60mm lens to get a field of view 2m wide. 9mm is WAY too wide to give you usable detail at that range.

[boily 0]

its just for my house all i want is a picture that is good enough to make out the persons face my budget would be about 3500

 

thanks

[rory 0]

You will need to set the camera to zoom in on the area where the person will be, with say a 5-50mm/7-70mm lens camera, otherwise not going to get a face at that distance, other then as mentioned going Megapixel, which seems to be out of budget especially if you also want to see something at night. If that was 25' then sure but I figure meters is much further, even though we dont use that measurement here If you dont have the budget then just go with the 4-9mm and you will get what you get. When you get into faces and licence plates, details like that, it normally goes out of the average home user budget.

[cglaeser 0]

its just for my house all i want is a picture that is good enough to make out the persons face my budget would be about 3500

 

Your budget is reasonable, but be aware that person identification is a challenging problem. Is this during the day, night, or both? Indoors, outdoors, or both? Is this a person you know or a total stranger? Why do you want to ID them? For example, someone breaks into your car, and you want to give an ID to the police, something like that?

 

Best,

Christopher

[boily 0]

its if someone tries to break in my car or house.

thanks

[jonb300 0]

analog cameras have fixed resolution( or image size) try pointing the camera at places the person will most likely to pass and set the camera for facial recognition. i read somewhere that acceptable facial recognition differs from 40-80 pixels (face size). hope i am right on this