New Install: Camera Mount and Focal Length Questions

[joltman]

My wife and I have decided it's time to get security cameras for the house. We've been seeing posts in the neighborhood's Facebook and NextDoor groups about people coming around and checking for boxes on porches. I don't want that to turn into breaking and entering.

I've been reading a lot here and have read through the Cliffs Notes and wiki. My plan is to cover my front door with one camera at ID level, and another higher up to capture boxes sitting on the porch. I'll be installing 2 cameras underneath the lights on the garage (about 5.5 feet off the ground) that will criss cross the front drive. I'll have another camera at the back garage door entrance, and one in the garage. The last camera will be at the back sliding glass door. I don't have the budget right now to do what I'd like and get enough cameras to monitor all sides of the house and the basement window wells. However, I feel it's unlikely that someone will want to hop over a 5' fence to get to our house in particular. That's more work than just hitting another house.

My purchase list is as follows:

(3) Dahua IP Camera IPC-HDW5231R-ZE (Two External Garage, one Internal Garage)
(3) Dahua Wall Mount PFB203W for the above turrets
(4) Dahua IP Camera IPC-HDBW4231F-AS (Front Door, Front Porch, Back Garage Door, Back Sliding Door)
(1) 24 Port Patch Panel
(1) Hinge Wall Mount for Patch Panel
(7) RJ45 Keystone Jacks
(1) PC for Blue Iris (software already purchased)
I've already got CAT6 cable (solid wire) and fishing tape, punchdown tool, velcro, PoE switch, etc.

As I said, I've read the cliffs notes. However, I'm still confused about the proper focal length of the lens on the IPC-HDBW4231F-AS. In the attached photo, I can aim the lens down a bit and still get someone's face (maybe even do corridor mode). The picture of the front door was taken at about 10-13' away from the camera's location. I've tried to figure out the radius calculation in the cliffs notes, but that hasn't made a lot of sense to me.

Radius = (( Horizontal Res / 100 ppf ) * ( 360 / Angle ))/2*Pi

What is the ANGLE? Is that HFOV? Is that the angle that the camera looks up/down at a person's face? I'm sure it's something obvious, but I'm not understanding. I assume that number would then somehow help me choose the correct lens? Howso?

The front door ID camera will be under the light fixture. I don't know if I'll see any light spillage from the light above, but we'll see. The front lights have a built in photodetector. I simply leave the switch in the on position, and the outside lights turn on and off with sunset and sunrise. I'm slightly concerned about the dome and sunlight. In the winter months, direct sun will hit the front door dome for a couple hours in the morning and several in the evening. In the summer, the sun will be too high in the sky and shouldn't hit the dome at all. Should I be worried about that? If so, is there a better suggestion of camera that isn't a turret (I feel that's too large for the front door). I suppose I could mount the camera on the LEFT side of the door, but I wouldn't get the same view of the person walking up the driveway onto the stairs.

For the garage door I'll use a similar lens to the front door. The back door doesn't have a lot of room between the fence and the door, so there won't be a long distance I need to zoom into and ID a person. I would imagine the back patio door is the same. Direct sun will hit the garage door camera in the summer for several hours (noon to 3?) and the back patio door from say 1pm to dusk. Again, is this a major concern? If so, what should I be considering that's not a turret?

How do I get a waterproof connection between the camera body or mount and the house? Should I use some silicone caulk along the top and sides of the camera mount to keep out water (IPFB203W)? Same with the 4231 camera? Or should I get the waterproof junction box for the 4231? Do any of the boxes (PFA130-E or PFA137) line up perfectly with the body of the 4231 camera?

That was a lot of information. Sorry about that. Just trying to be thorough. Let me know if I've messed up in any of my ideas or if there's a better way to do this. Thanks!

 

[mat200]

..

As I said, I've read the cliffs notes. However, I'm still confused about the proper focal length of the lens on the IPC-HDBW4231F-AS. In the attached photo, I can aim the lens down a bit and still get someone's face (maybe even do corridor mode). The picture of the front door was taken at about 10-13' away from the camera's location. I've tried to figure out the radius calculation in the cliffs notes, but that hasn't made a lot of sense to me.

Radius = (( Horizontal Res / 100 ppf ) * ( 360 / Angle ))/2*Pi

What is the ANGLE? Is that HFOV? Is that the angle that the camera looks up/down at a person's face? I'm sure it's something obvious, but I'm not understanding. I assume that number would then somehow help me choose the correct lens? Howso?

The front door ID camera will be under the light fixture. I don't know if I'll see any light spillage from the light above, but we'll see. The front lights have a built in photodetector. I simply leave the switch in the on position, and the outside lights turn on and off with sunset and sunrise. I'm slightly concerned about the dome and sunlight. In the winter months, direct sun will hit the front door dome for a couple hours in the morning and several in the evening. In the summer, the sun will be too high in the sky and shouldn't hit the dome at all. Should I be worried about that? ..

Aloha @joltman

Nice looking home.

1) my math on a 2MP camera:
Dahua IPC-HDW4231EM-AS starlight fixed lens 1080p 1920x1080
w/2.8mm lens FOV H 110 degrees: 10 feet { area covered 95.94 sq feet covered }
w/3.6mm lens FOV H 87 degrees: 12.65 feet { 121.43 sq feet covered }
w/6mm lens FOV H 51 degrees: 21.58 feet { 207.16 sq feet covered }

In general I do not like to use a 2.8mm lens unless I put it where someone will be very close to the camera, such as by the front door.

2) mini-dome and sunlight - if the amount of exposure to UV is limited, then I would not worry too much about the degradation of the plastic dome. It takes time - if you reduce the exposure 50% then in theory it will last 2x longer. This probably will work well enough - as by the time you notice the degradation you probably are really to upgrade the camera. The times where I see this as problematic is when the camera dome is exposed all the time to UV ( no shade at all ).

3) mini-dome and low light / IR issues - if you can have enough light on to keep the camera in color mode - then you will not have to worry about this.

4) remember to test your placement ideas - this will help a lot.

5) junction boxes / wall mounts are helpful if you can not easily stuff the pig tail back into the wall.

As you have an attached garage with fiberglass insulation you maybe able to stuff the pig tail / connection back into the wall without to many issues. Normally more of an issue with the spray foam insulation.

I used silicone caulk to seal the top and sides of the base of the cameras / junction box when attaching them to the wall.

 

[mat200]

Oh, and do remember to pull extra cat5e/6 cables while you are doing this.

Especially when you do the run by the front door - one day you may want a IP POE video doorbell / intercom there.

 

[joltman]

Thank you so much for responding!

1) my math on a 2MP camera:
Dahua IPC-HDW4231EM-AS starlight fixed lens 1080p 1920x1080
w/2.8mm lens FOV H 110 degrees: 10 feet { area covered 95.94 sq feet covered }
w/3.6mm lens FOV H 87 degrees: 12.65 feet { 121.43 sq feet covered }
w/6mm lens FOV H 51 degrees: 21.58 feet { 207.16 sq feet covered }

It sounds like I could use the 2.8mm lens or the 3.6mm lens. It also sounds like ANGLE variable in the calculation in the cliffs notes does mean HFOV. The front door camera could probably use either and come out OK. If 3.6mm, then it would catch people coming up to the stairs looking for packages. 3.6mm would also probably do well for up close shots, would you agree?

2) mini-dome and sunlight - if the amount of exposure to UV is limited, then I would not worry too much about the degradation of the plastic dome. It takes time - if you reduce the exposure 50% then in theory it will last 2x longer. This probably will work well enough - as by the time you notice the degradation you probably are really to upgrade the camera. The times where I see this as problematic is when the camera dome is exposed all the time to UV ( no shade at all ).

This is my big concern. I've got 1 location for sure that will be in direct sunlight all summer from noon to 8pm. I'm looking around at any camera manufacturer that might be able to handle this and be compatible with BlueIris. Do you have any thoughts?

5) junction boxes / wall mounts are helpful if you can not easily stuff the pig tail back into the wall.

Does the Dahua IPC-HDBW4231F-AS fit perfectly over those junction boxes or is there a bit of overhang?

I will definitely be testing my placement with the bucket method. I just need to place my order with @EMPIRETECANDY first. I was hoping to buy it all in one shot. As I said, the only concern I have is that one camera that will be in direct Colorado sun for 8+ hours a day in the summertime. But if it's not a huge concern, then I'll pull the trigger on the whole deal. Thanks again!

 

[mat200]

..The front door camera could probably use either and come out OK. If 3.6mm, then it would catch people coming up to the stairs looking for packages. 3.6mm would also probably do well for up close shots, would you agree?
..
Does the Dahua IPC-HDBW4231F-AS fit perfectly over those junction boxes or is there a bit of overhang?
..

Hi @joltman

Even with a 2.8mm lens you may not be able to both view the package drop area and a person at the front door

I suggest considering the following dual lens camera if you want to do that with just one camera
Review-Dahua IPC-HDBW4231F-E2-M Dual Starlight Cam

( other option is to have another camera on the side also covering the front door and package drop area )


In terms of junction boxes - some fit the camera very well. ( PFA137 for example .. ) some fit numerous cameras but not as nicely for all the cameras - example PFA121, PFA122 iirc )

For the mini-dome wedge cameras at eye level by the front door I think mounting it on top of a junction box makes it stick out of the wall too much.

I would try to find a way to stuff the connection back into the wall cavity, or event find some sort of sliding product which will help out.

 

[IAmATeaf]

@mat200 can you explain the distance in your calculations, I don’t understand what the distance means.

 

[joltman]

@mat200 can you explain the distance in your calculations, I don’t understand what the distance means.

From what I understand, you want at least 100ppf (pixels per face) for the I in the DORI acronym (Identification). At the given distance, you should have 100 pixels. Anything closer, and you'll have more pixels and that should give better a better picture for identification.

So with the 3.6mm lens I'm looking at, I should be able to identify someone in challenging conditions at ~12 ft. I guess I don't know enough about lenses to understand how something is in focus between, let's say, 12 ft to 2 ft. I would guess the camera has an autofocus?

I'm still concerned about the Dahua 4321 camera's plastic dome being in sunlight for so long. I don't even think Axis makes a camera with a glass dome to survive that brutal Colorado sun. But maybe I'm wrong?

 

[mat200]

@mat200 can you explain the distance in your calculations, I don’t understand what the distance means.

Hi @IAmATeaf

Joltman describes it well, more details are also in the cliff notes.

Remember, this is theoretical based on effective pixels. In real terms the ID distance will typically be less due to low light, noisy image, ghosting/blurry,...

 

[Mike]

Check the tools section, there is a focal calculator in there