Number plates - more megapixels? lens choice? settings?

gth

Young grasshopper
Joined
Dec 11, 2014
Messages
49
Reaction score
3
I'm very satisfied with Hikvision, including several good outcomes after thefts. Each time I was asked if there was "a better view of the number plate?". I'm not permitted to post imagery but suffice to say I'm struggling to improve the footage. Vehicles are only between 10-15 metres from the camera.

1. Currently using DS-2CD2332-I + 4mm lens. Settings are: 2048x1536, VBR (8192 max), Highest Quality, 2 fps, Iframe 50, WDR off, DNR off, exposure 1/25 with 100 gain, "AWB1", all Image Adjustments set to "50".

2. Recording 24x7 with Blue Iris 4 balancing storage requirements vs. CPU vs. image quality. Settings are: 2048x1536, 2fps, 3mb receive buffer, direct-to-disc (h.264). The footage is very clear, but just that last step of getting clearly readable plates is eluding me. We are getting results using partially readable plates.

Ideas:

a) I could swap the camera with a DS-2CD2335-I but I'm not aware of any relevant improvements? Or should I splurge and try one of the newer 4mp Hikvision cameras?

b) A longer exposure might look clearer but goes blurry on movement, correct? Since suspicious targets tend to move I haven't gone that route.

c) The low FPS is mainly due to CPU usage - if I get lucky and the number plate remains still it's quite readable in daylight; I don't expect readable plates at night.

d) Should I try a different lens?


Suggestions welcome.
 

hook3m

Pulling my weight
Joined
Sep 8, 2015
Messages
395
Reaction score
229
Location
USA
You're not going to get readable plates with a 4mm lens at that distance. Going to a 4MP camera will help slightly with digital zooming but not much. You will need to go to a 12mm lens in order to get a good read on plates. I have a 2032 with a 12mm lens and I can read every plate that turns down the street in front of my house during the day. Distance is about 20-25 meters. At night I am using the Huisun 10x PTZ mini-bullet as I can't get the 2032 dialed in to read them at night. Attached is a sample image from my 2032 12mm.


Car - Copy.jpg
 
Last edited by a moderator:

gth

Young grasshopper
Joined
Dec 11, 2014
Messages
49
Reaction score
3
Very much appreciate all the replies - been reading up on the Huisun 10x threads (specs page?). Very different look compared to the hik turret but can't deny adding PTZ would probably put me into early stages of addiction (4 hiks cameras so far! :)

Will look at pricing - definitely a fan of PoE, so all the better. I've got an analog a/v background plus IT so this is all good fun.

Boss with the purse strings says no posting images of the area - various drama (legal and otherwise) best avoided.

- G.
 

hook3m

Pulling my weight
Joined
Sep 8, 2015
Messages
395
Reaction score
229
Location
USA
Whatever route you decide, you can't go wrong with a Huisun PTZ. For the price it's an awesome camera.
 
Top