HFW5831E vs HFW2831T

loopforever

loopforever

n3wb
Jan 7, 2019
17
9
Nesconset, NY
Hi all,

I see that the 2MP Starlight cameras are highly recommended and without question ideal for low light situations. I think however, for my purposes, I care more about performance and resolution when there is ample ambient light (day time, and night time when the property is well lit both from house lights and street lamps).

There have been some reviews here of the fixed lens 1831E (Lite line, 1/1.8") and the varifocal 5831E (Eco Savvy line, 1/2.5" STARVIS) and they seem quite comparable.

I really like the varifocal 2831T (Lite line, 1/1.8") and I suspect that it is more than sufficient for my purposes. But I am confused because it seems to me a better value than the 5831E model in the "Eco Savvy Pro Line".
  • 2831T has a larger sensor, though not a "STARVIS", but reviews posted here seem to show acceptable low light performance as far it can be expected in the 8MP range. Having never owned a camera before I don't know how to equate "minimum illumination" specs to real world performance.
  • 2831T while supporting one fewer substream (fine for me), offers higher FPS @ 4K on the main stream
  • 2831T-ZAS incorporates a microphone while 5831E must be added separately
  • 2831T offers roughly equivalent IVS features, with the exception of "Face Detection" and "Object Missing"
https://www.dahuasecurity.com/asset/upload/download/DH-IPC-HFW5831E-ZE_Datasheet_20170630.pdf
https://www.dahuasecurity.com/asset...25/DH-IPC-HFW2831T-ZAS_Datasheet_20181224.pdf

I am totally a novice and the extent of my knowledge comes from the many things I have read on this forum. Is there anything significant I am overlooking with these two cameras and would I regret going with the "lower end" 2831T over the 5831E?

Thanks in advance!
- Matt
 
loopforever said:
But I am confused because it seems to me a better value than the 5831E model in the "Eco Savvy Pro Line".
Click to expand...
I think part of that comes from the fact that the 2831T-AS is pretty much a brand-new model, whereas the 5831 is coming up on being two years old. Thanks for calling out the 2831T-AS model -- I hadn't noticed they had a bullet with a mic built-in!

The 1831/2831 models are getting the most recommendations for folks that need to have more than 2MP because like you said, their larger 1/1.8" sensors do better in low-light as compared to the smaller 1/2.5" sensors found in the older 5831 models.

For "minimum illumination specs", I don't know if there is a better way to use them, but compare them between models to get a general feel for how their low-light ability does. I use the ( Color,1/30s,30IRE) spec, as that's the fastest shutter speed they post specs for. At night, on some of my Starlight cameras, I have to run at 2x-3x the speed to reduce motion blur.

.05 lux = 2MP Starlights (most)
.09 lux = 2831T-AS
.20 lux = 5831

Based those minimum illumination specs, compared to most Starlight models, it looks like the 2831T-AS needs 2x more light to stay in color mode, and the 5831 needs 4x more light. I'm assuming that once the cameras switch to B/W mode, their low-light performances stay ranked the same. Hopefully others with more experience will chime in with how they use the min. illumination specs.

Regarding the 2381T-AS vs the 5831, I don't think you'll find many folks that will suggest going with the 5831 nowadays. If you find the 2831T-AS won't let you ID folks at night, you can always supplement with a 5231 Starlight varifocal zoomed in on a chokepoint that folks usually pass through.
 
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aristobrat, thanks for your feedback -- that basically answers it for me! It definitely seems like 2831 is largely the right camera for me. I do have ONE use for the 5831-Z5E for ID and LPR at a long distance (shame there is no equivalent with the new sensor).

Your description of the LUX ratings helps tremendously, just to put things in relative terms. In my case the house is always well lit, and I plan on adding more low voltage lighting in the spring. So I feel better with the decision to go with the 8MP 2831T over the 2MP 5231 for most applications.

I think overall my setup is going to look like this:

1x IPC-HDW4831EM-ASE (2.8mm Fixed, for wide angle approach in close proximity to house)
1x IPC-HFW5831E-Z5E (for Face ID and LPR @ 75-110ft, for street and driveway approach)
5x IPC-HFW2831T-ZAS (for general purpose)

Which I calculated on IPVM (screenshots attached) and this seems to give me decent coverage with minimal blindspots with PPF ~90-100 for any reasonable approach to the house.
 

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I think aristobrat's explanation of low light specs is as good as it gets. One thing I might suggest is to just get one 2831t at first and try it out at different locations to see how it works before committing to all five. What looks like a lot of light to me and you, doesn't always translate that way to cams. Especially 8mp cams.
 
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If you haven't already had a chance to go through the LPR sub-forum, it might be worth checking out a couple of posts. To capture LPR at night, the settings of the camera have to be tweaked (no big deal), but the result is usually that the camera will only see reflective plates at night. Other stuff (people, scenery, etc) usually come out too dark for the camera to effectively see. I'm thinking that at night, there's a chance that you won't be able to use the same camera to do both LPR and detect people. The usual LPR camera suggestion for 100ft away is the HFW5231-Z12. Might be work searching to see if folks have posted with experiences using the HFW5831-Z5.

x2 on @BillG's comment to trying out one cam first before jumping all in. If you can, snag one 2831T and maybe the 4831 and make sure they meet your expectations.

One thing to keep in mind when you see "still images" from a camera at night is that still images almost always look focused and detailed, but video of someone moving in the same scene will often have blur (especially on details like the face). So when the IVPM calculator shows you the simulated image of what the guy holding the license plate will look at night, that's probably pretty accurate... for a still image. What's hard to do (at least for me) is use the quality of that still image to try and figure out how much blur will be in the video when the guy starts walking towards the camera. As good as the 2MP Starlights do in low-light, it's not uncommon for them to have some blur... they are usually the cameras with the least amount of blur.

If you want to use the 4831/5831 to tell if a person is walking up to your house at night, I think that will probably work. You can probably ID people that you know. It'll prob. be difficult to ID someone you're unfamiliar with. And if the person is moving quickly (i.e. running up to your house at night), I'd expect it to be too blurry for much good.

Your lighting really may be good enough for all of the 4K(8MP) cameras to work well, but @BillG's thought is what I'd recommend -- it'd probably a good idea to verify the quality is what you want (esp. with blur on movement) before ordering the whole lot.
 
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"I'm assuming that once the cameras switch to B/W mode, their low-light performances stay ranked the same."

I would only add that this may vary depending on the IR LED's supported by the cam and the current zoom level (if supported by the cam)

Also, for LPR at ~100ft, I find I need more zoom than a 12mm lens provides. I use ~50mm, but I'm also at a pretty high angle from the vehicle's path of travel (~40 degrees,) and I must admit I haven't tried a 5231 for LPR in my setup...
 
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Thanks everyone for all the insightful comments!

Hmm, perhaps automated LPR is unreasonable at night due to the compromise of settings on that camera which would make it useless for any other purpose. This might only be attainable with an additional, purposefully configured camera, and might not be worth the trouble. I suppose it would be good enough if I could visually review the footage, versus needing to automate the LP capture. The other day I had people stopped in front of my driveway taking pictures of the house, and I was just hoping that I could a) see who these people are, b) know what car they are driving and if they are returning at other times during the day. Attached a pic of what the approach looks like from the street; where a car might be parked, or an individual might approach most easily.

Edit: For reference, it's 72 feet from the garage door to the edge of the driveway.

Motion blur definitely seems to be a big issue from all of the footage I've seen in reviews here and the comments you all have made.

As for cars driving by "fast", I don't really care to identify them or capture the LP. I'm more worried about someone slowing down or stopping. Of course if I could read the plates with a universal configuration I wouldn't complain...but it does seem I can't have it all! (Without adding more cameras :p) The HFW5231-Z12 looks interesting, but IPVM calculator is telling me I'd only be getting 44 PPF@100ft.

As for people "running" towards the house... In one regard the positioning of my cameras and the slope of the driveway might be to my advantage, because even a camera mounted 8'-10' off the ground is still essentially "eye level" for part of the driveway (ie. driveway slopes down from the street). This might possibly enable more usable frames to be captured where a person's face might not be obscured by a hat or something? The area is lit by no less than 3 lights

Thanks again everyone for the feedback, it is really helping me understand what is going to work for my set up!
 

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the Z12 is a 12x zoom, up to 60mm, which results in over 200PPF at 100ft for a 2Mp cam...
I can see how that would make a FANTASTIC LPR cam.

(In IPVM calculator, scroll down on the right to find "Advanced: Lens, IR" section - the default for vari-focals tends to be the WIDEST FoV)
 
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loopforever said:
The HFW5231-Z12 looks interesting, but IPVM calculator is telling me I'd only be getting 44 PPF@100ft.
Click to expand...
For me, the IPVM calculator doesn't seem to work as expected when I add the ZE model... it doesn't give me the slider to change the zoom on this model.

Using the non-PE version of the camera (which IIRC is optically the same as the ZE model), the zoom slider is there. I can def. get 100 PPF at 100 feet, with "the catch" being that FOV is only about 15-16 feet wide at that zoom level.

Nice looking house/yard BTW!
 
Well, thank you guys again. I had a suspicion that PPF didn't seem right...certainly the videos posted here looked way better than 44 PPF! I didn't see that some cameras have the option to configure the zoom in the calculator. That is tremendously helpful and makes a big difference in the planning.

I might just pickup at HFW5231-Z12 just to play with it. I'm sure it'll find a good home somewhere on the property. And if nothing else, it can be mounted next to the HFW5831E-Z5E and one of them can do LPR while the other can be general purpose...depending on which performs better at either task at ~100ft.

Thanks again! It might be a few months before the cameras arrive and all the cabling is run, but I'll be sure to follow up with my results!
 
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loopforever said:
  • 2831T-ZAS incorporates a microphone while 5831E must be added separately
Click to expand...
aristobrat said:
Thanks for calling out the 2831T-AS model -- I hadn't noticed they had a bullet with a mic built-in!
Click to expand...
I dont believe it has a built in mic. The spec sheet indicates audio in/out and alarm in/out. This would be in line with the rest of the dahua bullets that dont have a built in mic. It is nice to see audio and alarm connections though.
Interestingly the spec sheet also calls this bullet a dome in the title.
 
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I think you are correct. I misinterpreted the "A" as meaning it had a mic. In the Dahua comparison tool, models with audio in/out are distinctly different from models with built-in mics. I didn't notice that...thanks for pointing it out.

If a model has audio in, is that simply a 3.5mm jack or RCA equivalent? Meaning you'd need a clunky POE splitter to provide power to the camera and 12V to the microphone?

Is it wishful thinking or are there any cameras out there that (absent an internal mic) simplify the wiring in the junction box by offering 12V output for an external mic?
 
loopforever said:
I think you are correct. I misinterpreted the "A" as meaning it had a mic. In the Dahua comparison tool, models with audio in/out are distinctly different from models with built-in mics. I didn't notice that...thanks for pointing it out.

If a model has audio in, is that simply a 3.5mm jack or RCA equivalent? Meaning you'd need a clunky POE splitter to provide power to the camera and 12V to the microphone?

Is it wishful thinking or are there any cameras out there that (absent an internal mic) simplify the wiring in the junction box by offering 12V output for an external mic?
Click to expand...
You would need power. You can run a second cable ...there are other methods. There are certain uniview cameras - i believe only some domes, that can output audio.
The connection is most likely bare wire.
 
fenderman said:
You would need power. You can run a second cable ...there are other methods. There are certain uniview cameras - i believe only some domes, that can output audio.
The connection is most likely bare wire.
Click to expand...

At the risk of sounding like a dummy, I'm going to throw this out there in the event a) I'm understanding the spec sheet correctly, b) this would actually work, because c) it would be really neat...

I see this microphone has been used successfully with a POE splitter in a few threads here: https://www.amazon.com/gp/product/B00M5P7HCW/ref=ask_ql_qh_dp_hza . It operates at 12VDC @ 17mA.

The spec sheet for HFW2831T-ZAS shows that it has an Alarm Out which supplies 12VDC @ 300mA. Normally I suspect people are using this to momentarily trigger a relay and some externally powered device that operates at a higher voltage.

But, if you go from this bare wire to a barrel jack connector... the Alarm Out provides more than ample current to power an external microphone like the one above. This comes with the added effect of being able to trigger the microphone on or off by triggering the alarm itself on or off. Of course the downside would be that the alarm itself would be unusable (and constantly on)...but the up side is no bulky POE splitter needed.
 
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loopforever said:
At the risk of sounding like a dummy, I'm going to throw this out there in the event a) I'm understanding the spec sheet correctly, b) this would actually work, because c) it would be really neat...

I see this microphone has been used successfully with a POE splitter in a few threads here: https://www.amazon.com/gp/product/B00M5P7HCW/ref=ask_ql_qh_dp_hza . It operates at 12VDC @ 17mA.

The spec sheet for HFW2831T-ZAS shows that it has an Alarm Out which supplies 12VDC @ 300mA. Normally I suspect people are using this to momentarily trigger a relay and some externally powered device that operates at a higher voltage.

But, if you go from this bare wire to a barrel jack connector... the Alarm Out provides more than ample current to power an external microphone like the one above. This comes with the added effect of being able to trigger the microphone on or off by triggering the alarm itself on or off. Of course the downside would be that the alarm itself would be unusable (and constantly on)...but the up side is no bulky POE splitter needed.
Click to expand...
The alarm out doesn't supply any power... that is power you need to insert into the circuit for it to work.
 
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