Help on camera choice, particularly focal length

Chuck Claunch

Chuck Claunch

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Dec 23, 2015
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I had my truck stolen out of my driveway a while back, and even though I had cameras, it's a very old system and really sucks. I got an IP camera (A Hikvision DS-2CD2135F-IS (2.8mm 3MP)) and have Blue Iris set up on my server and am all set, but now we have a baby on the way. I was thinking maybe this 2.8mm camera would be well suited for baby monitor duty. I've toyed around with various online focal length calculators and still don't quite understand exactly what focal length I need for each application. My driveway cam has a pretty good field of view, though I don't know the focal length. The camera is mounted on the soffit about 8' up right next to the garage and pointing out at the driveway. Here's the video for comparison (grrr I get pissed every time I watch it!)



The baby monitor cam would be likely mounted on the ceiling right above the crib or near it, and about 8' overall from the baby. I wouldn't care if I captured the rest of the room, just the baby himself.

So what focal length should I get for these two camera choices? Do any of the other specs really matter (obviously need outdoor ratings and IR on the outdoor one) Any specific camera suggestions?
 
4mm will do. You can always zoom in with software though. I use 2.8mm for baby cam in the opposite corner of the crib, but I like to capture entire room. There are some cheap options with motorozied varifocal lens that you might want to consider. I have one cam that I can zoom from 2.8-12mm.

This is the size of the dome you have, but there are some smaller options available as well:
https://www.ipcamtalk.com/showthread.php/9362-69-motorized-varifocal-4x-(2-8mm-12mm)-Longse
 
ipvm.com/calculator (keep ppf > 100 at night for ID capabilities)

driveways in the burbs usually need 4-8mm depending on length.. dont put the camera on the corner there.. put it in the middle looking down the center line with 2 vehicles parked side by side.. dont put domes outside, use turrets instead.
 
Thanks guys. That calculator is awesome. It looks like 4mm should work. The front of our house doesn't lend well to me putting it anywhere but that corner, as the front gable is very tall, plus the WAF is very low :(. The good news is since the truck theft she's more willing to allow more cameras so I think if I put another one on the other end with a longer focal length it will cover anything this corner cam doesn't.

I am curious, what's the major reasoning for turrents vs domes outside? (also bullets for that matter)

Also, on the varifocal, does that mean it's "automatic" focus?
 
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There is plenty of discussion on turrets vs domes in summary, less chance of IR reflection, better IR and ease of adustment/mounting

The VF has automatic focus and zoom. This is old UI, now it's more like Hikvision, but the functionality is the same (start at minute 3:35):

 
i'll add that plastic domes will age poorly with exposure to high levels of UV radiation.. put one in the sun and in a couple years the image will be cloudy; turrets/bullets have glass lens covers and typically all metal housing.. no plastic to degrade.
 
Dahua turret is all plastic
 
depends on model, there are all metal dahua turrets too.
 
Also I am finding the need for a lot more light out there in general. Put one of the HIkvsion owl turrents out there with a white car the black pickup is totally gone in the display. Will be adding some more lights at about eye level to the edges of the garage and probably another along the side of the garage. Might check into some motion lights off solar as electricity is $0.10 a kwh these days and that adds up over the years.
 
Sure, but depends how much light really and cam sensor sensitivity as well as lens. In the video above, both cams using good low light sensors. Hikvision/Dahua equivalent cams will not be as good without additional light.
 
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