Looking for input before final mounting

[58chev]

Looking for input mainly on the two cameras I will be mounting on the front of my home.

Bungalow, soffit approx 10' high. property is 50' wide.
All Hikvision Turret Cameras and NVR. Will be running cables through the attic of the house and already have a line out to the garage.


Camera 1 = DS-2CD2355FWD-I - 4mm
Camera 2 = DS-2CD2355FWD-I - 2.8mm

Just unsure if I should have

Camera 1 to monitor the walkway and front entrance.
Camera 2 to monitor the driveway.

OR

Camera 1 & 2 to cross each other and 1 - monitor the drive and 2 to monitor the walkway and front entrance.

Camera 3 - DS-2CD2355FWD-I - 2.8mm
Will monitor the garage in the backyard.

Camera 4 - DS-2CD2335FWD-I - 2.8mm
Will be mounted on the garage soffit (8' high) facing the sliding patio doors at the rear of the house.

 

[looney2ns]

You want to know who did it, not just what happened.
2.8mm lens makes it difficult to ID a face, unless the perp is 12-15ft away.

Get familiar with this: Camera Calculator / Design Software keep PPF>100, tutorial upper left of page.

 

[mat200]

Looking for input mainly on the two cameras I will be mounting on the front of my home. ..

Welcome 58chev,

Do not be afraid to add more cameras to increase your chances of getting good ID images of potential suspects.

Also welcome to the forum,

Have fun joining us here.

 

[truglo]

If you're like me, and you prefer viewing a situation through the lens of mathematics, make note of these basic equations:

D = Distance from lens to object
Theta = FOV of lens (angle)
O = Half horizontal FOV (object plane)
R = Horizontal Pixels
A = Area Resolution (PPF)
V = vertical pixels (1080)
ar = aspect ratio (16:9=1.778)

R = V * ar
A = R / (2*O)
tan(Theta/2) = O/D
D = R / (2*A*tan(Theta/2))

I used that to make a spreadsheet which I use to brainstorm/design/verify camera selection/placement/coverage. I found a table with ppf vs FOV angle and distance to be the most useful. Hope this helps someone.

Kev

 

[mat200]

If you're like me, and you prefer viewing a situation through the lens of mathematics, make note of these basic equations:

D = Distance from lens to object
Theta = FOV of lens (angle)
O = Half horizontal FOV (object plane)
R = Horizontal Pixels
A = Area Resolution (PPF)
V = vertical pixels (1080)
ar = aspect ratio (16:9=1.778)

R = V * ar
A = R / (2*O)
tan(Theta/2) = O/D
D = R / (2*A*tan(Theta/2))

I used that to make a spreadsheet which I use to brainstorm/design/verify camera selection/placement/coverage. I found a table with ppf vs FOV angle and distance to be the most useful. Hope this helps someone.

Kev

Hi Kev,

I am finding that some vendors do not provide enough details for FOV.

Sometimes they only post one FOV - and it turns out to be Horizontal FOV, other times it is Diagonal FOV.

Are you seeing the same?

Thanks

 

[truglo]

I have only been working with the well known cams in these forums. It doesn't surprise me that manufacturers tend to obfuscate that critical bit of info. I haven't dug into it yet, but I figure there may be a way to calc H fov based on focal length (known for almost all cams) and sensor (ie 2mp = 1080 vertical). Someone else may chime in with that info before long. If not I'll see if I can't derive something that works directly with more commonly available cam specs.

Kev

 

[mat200]

I have only been working with the well known cams in these forums. It doesn't surprise me that manufacturers tend to obfuscate that critical bit of info. I haven't dug into it yet, but I figure there may be a way to calc H fov based on focal length (known for almost all cams) and sensor (ie 2mp = 1080 vertical). Someone else may chime in with that info before long. If not I'll see if I can't derive something that works directly with more commonly available cam specs.

Kev

Hi Kev,

Some of the products being sold as security camera solutions to consumer do not even list the focal length, so it's been rather frustrating at times to get good data without having to dig or chat with vendors.