Review-Dahua IPC-HFW1831C-PIR 4k Mini Bullet

Discussion in 'Dahua' started by looney2ns, Jan 17, 2019.

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  1. looney2ns

    looney2ns IPCT Contributor

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    Search is your friend. https://ipcamtalk.com/threads/dahua-api-pdf-version-1-67.19177/
     
  2. greg_mitch

    greg_mitch Young grasshopper

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  3. bonehead76

    bonehead76 n3wb

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    @looney2ns

    that worked, thank you!
     
  4. sdl0311

    sdl0311 n3wb

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    So after a few days of testing and getting assistance from @aristobrat, I've been able to reduce false alarms by about 90%. I originally had 3 cross zones in BI set up that helped reduce some of my false alerts, but the shade from my truck and house (during the day) and the headlights of veh's (during night) were still triggering a few false alerts. What I ended up doing is similar to aristobrat, which was to disable all motion detection in BI and dahua settings. He then walked me through with setting up a curl script in alerts to keep the dahua camera motion detection settings from turning on each time a change was made. Now I use strictly the camera's PIR settings to trigger my alerts. I created two regions because my american flag kept triggering the one region. So now I have one region that is very sensitive which is where I get most foot traffic, and the other region is covering the flag. I'm still playing with the sensitivity and threshold settings, but so far, I have not missed an important trigger (ie, someone walking to or from my house), and have reduced false alerts significantly. In case anyone else has this camera, I recommend giving it a try if you are getting a lot of false alerts. I also can't wait to see how well Sentry Smart Alert works once it gets incorporated with Blue Iris. Thanks again to all those that provide their time and knowledge to this forum. It is much appreciated whether you know it or not. :)
    Annotation 2019-03-06 143119.jpg Annotation 2019-03-06 143154.jpg
     
  5. aristobrat

    aristobrat IPCT Contributor

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    @sdl0311, looks like a potted plant tipped over today and set of the PIR on my 1831. The plant was about 40ft from the camera, so finding it hard to believe. The cardboard boxes on the porch were also flapping a bit, but they were doing that all day with no alerts. In this alert, the boxes were flapping and the plant way back there tipped over. Weird.

    0654FCF7-CE44-4470-BD8F-18FA2B4DDDA4.jpeg
     
  6. fenderman

    fenderman Staff Member

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    While I dont think the PIR sensor has that kind of range, it is interesting to note that plants emit more IR than cardboard and can cause false alerts.
     
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  7. lulu5kamz

    lulu5kamz Getting comfortable

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    I just got one of these cameras from Andy. Ordered it on Sunday night and it arrived yesterday (Wednesday). Decided to test it out so I plugged it in and pointed it at a TV which was turned on. Before I even logged in the first time the alarm went off from the PIR sensor seeing the TV. I was surprised by the light and alarm. :)
     
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  8. CCTVCam

    CCTVCam Pulling my weight

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    It's a real pity and a puzzle to me as to why they haven't put this sensor into all their other 4K cameras. The performance looks sublime especially at night time colour and especially given the price. You pay much more for for a 4831 or 5831 model but get a poorer performing sensor. Confused. :confused::smash:

    Other than the mini bullet format and a slightly cheap looking SD slot / SD eject mechanism, this looks a great camera for a great price.
     
  9. fenderman

    fenderman Staff Member

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    Its actually an average sensor and not great in low light/night and likely the same as in those two cams. Dahua has much better 1/1.8 sensors in the 1831/2831 full size bullets
     
  10. CCTVCam

    CCTVCam Pulling my weight

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    I wouldn't have described it as average. From memory, the 4831 and 5831 use a 1/2.5" sensor which is significantly less sensitive in low light - around 0.05 lux, so around 20x worse low light performance.

    I noticed the 1831E 1.18" full sized version had slightly better low light performance than the C, but only slightly 0.003 vs 0.002 lux.
     
  11. Quindor

    Quindor Getting the hang of it

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    Interesting device with the combination of the light and alarm in there, that might actually scare people off. Sensors looks to be the same as the 5831 series with the 1/2.5" 8MP actually, so no-light scenario's are no go unless the IR (with probably some added IR).
     
  12. fenderman

    fenderman Staff Member

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    Dahua's lux ratings are misleading and false. This camera performs worse than the 5831 low light and has inferior fstop numbers. The 1831/2831 with the 1/1.8 sensor is orders of magnitude better.
     
  13. Quindor

    Quindor Getting the hang of it

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    I bought both the 1831 and 2381 for testing and will be doing a direct comparisons between those and the 5831's I have. I know another member did this also, but more footage is always good I think. Up until now it hasn't been a world of difference between those but I still need to do more tests. :)

    Weird that the cam from this topic would show much worse results then. May be the lens and not so much the sensor, I saw the same big difference in sharpness between the varifocal and fixed 8MP cameras of their 8MP 5 series cameras.
     
  14. fenderman

    fenderman Staff Member

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    You are not doing proper testing of you dont see a difference. This camera has inferior fstop numbers and that explains the difference.
     
  15. Quindor

    Quindor Getting the hang of it

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    Actually, yes and no. As I mentioned in my previous comment, this camera actually has a better F number for the lens then the fixed lenses in the 4/5 8Mpix series, but worse than the varifocal lenses, next to the difference in sharpness those lenses deliver. Still, reality can differ from the theoretical specs and might workout worse then on the other cameras, I do however believe it's the same sensor.

    Further I am not going to start a discussion with you again, certainly not in this topic but saying my tests are wrong because I don't see a difference is just idiotic, maybe I'm doing tests where indeed the difference is negligible, which makes the test and the result correct. That the results might be different in other testing scenarios can however also still be correct. Anyway, I'll post my results here when done and everyone can take a look for themselves. :)
     
  16. aristobrat

    aristobrat IPCT Contributor

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    FWIW, these are from Dahua's spec sheets and generally haven't been contested. I'd bet that most folks here would rate these camera's low-light abilities in this order:

    Code:
     5231: 2MP 1/2.8" - 0.05Lux/F1.4 (Color,1/30s,30IRE)
    1831E:  4K 1/1.8" - 0.08Lux/F1.6 (Color,1/30s,30IRE)
     5831:  4K 1/2.5" - 0.20Lux/F1.8 (Color,1/30s,30IRE)
    
    On the other hand, here's Dahua's spec for the 1831C-PIR. IMO, no way this camera rates "right behind" the newer 1/1.8" sensors for low-light performance. Not even close, ... at least not mine.

    Code:
    1831C:  4K 1/2.5" - 0.09Lux/F2.0 (Color,1/30s,30IRE)
    
    IMO, the fact that Lorex is selling these cameras is a good sign that there's nothing special about this sensor. I'd bet that Dahua is keeping the newer 4K 1/1.8" sensor to itself (like it's done with the 2MP 1/2.8" 'Starlight' sensor so far) and has let the consumer companies run with the smaller 4K 1/2.5" sensor.
     
    Last edited: Mar 8, 2019
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  17. CCTVCam

    CCTVCam Pulling my weight

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    I compared them at 1/3s, hence the differences being closer in your table.

    That's fair enough, Fenderman said the specs are inaccurate.

    What do you reckon is the best 4K performer then, the 1831E?
     
  18. Tuan

    Tuan n3wb

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    I would believe the 1831e is for the same price point if you dont need sound or varifocal. I'm crossing my fingers for a 4k 1/8 turrent to come out this year.
     
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  19. lulu5kamz

    lulu5kamz Getting comfortable

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