2.8mm or 4mm focal length to cover my drive?

[knwatkins]

Hi all, I'm looking at the Hikvison turrets and I'd like a bit of advice on what focal length to go for.

Here is the house. As you can see, the driveway is lower than the ground floor level by about 1m or so and slopes down to the road. The distance between the house and the front wall is 10m and the width of the driveway is 9m.

I was planning on mounting the camera at position 'C' but I'm open to different opinions.

My main question is, should I be looking at a focal length of 2.8mm or 4mm?

 

[Phil]

4mm

 

[knwatkins]

Thanks Phil.

What would the field of view be if the camera was mounted at around 2.5m and pointing downwards?

Are you able to recommend any specific models?

 

[Dan]

Hi @knwatkins

The 4mm should still be fine here, we would probably recommend something like the DS-2CD2346G2-IU 4MP AcuSense Turret camera (4mm).

 

[cymruchris]

Another option might be to look for a varifocal camera - if the budget allowed for it - you could look at something like the DS-2CD2H46G2-IZS- which has a 2.8mm-12mm lens (motorized zoom - not really suitable for watching and zooming - but more for easy setup from the ground once up and running).

Then you could adjust one camera to any specific area of view within the lens paramaters, and if after a couple of weeks you wanted to adjust the field of view - it's relatively simple to do (as long as the camera is pointing in the right direction).

​

 

[knwatkins]

Thanks for the suggestions. Really appreciate it. Ideally, I'd like to go for a 8MP camera. I've seen DS-2CD2387G2H-LIU with a 4mm lens that has the hybrid light feature which looks like a good thing to have. Any opinions on this one?

Chris, the idea of using a varifocal for experimentation is a great idea. I suppose I could use it initially to ascertain the correct focal length for the area and then redeploy it somewhere else afterwards.

 

[Dan]

Hi @knwatkins

Yes, the new Hybrid Light models are becoming a popular option but we would say that the ColorVu mode of these cameras works best if there is already ambient light (e.g. street lights, motion security lights, etc...) in the scene.

 

[David]

Thanks Phil.

What would the field of view be if the camera was mounted at around 2.5m and pointing downwards?

Are you able to recommend any specific models?

With FL 4mm you'll probably slightly overlook your neighbours drives, make sure they're ok with that. I really like the ColorVu cameras, especially if ambient street lighting is nearby.

Use-IP also have a 14 day buy and try policy.

David

 

[knwatkins]

Thanks David and Dan. The property is on a main road and there is a street light on the opposite side of the street so hopefully that will provide a good bit of background light.

I think the neighbours will be fine. They will probably welcome the added security!