How critical is Lux/Low light ability for night capture?

[Bitslizer]

I know everyone here pushes the IPC-HFW5421E-Z12E which got amazing night vision and low lux rating like 0.002 color.

Continuing my research for a poor man LPR. I see a few possibilities with zoom out to 94mm but....
How critical is that to producing legible night capture? Assuming the IR reach that far? Will a none starlight type with 0.01Lux work? Anyone had experiences/successes?

Thank You

 

[wittaj]

Starlight, ColorVu, etc. are marketing terms, so do not go by those.

None, or not many, are running the Z12E in color, so the color specs do not mean much.

You have to run a high shutter speed - most here run 1/2000 - and thus will be in B/W unless you have stadium quality light.

A few members here can get color based on a newer sensor size 1/1.8" and their specific location like lots of street lights and a stop sign.

Because you will probably be running B/W and a fast shutter - getting enough IR light is what is critical. Some here use an external IR illuminator to assist with that. But a good one for a longer distance is the cost of the Z12.

So the question really is how far is the distance between where your camera is and capturing plates and what camera are you thinking? If the 94mm poor man LPR you are looking at does not allow you to truly set things like shutter speed then it will not work....Until we know the camera and see if anyone has tried it, going by LUX and mm size is irrelevant...and I know from some of your other posts that you are looking at "poor man" cameras that do not see IR, so that would be another issue...

I have a cheapo cam with 120mm and even though it says I can set the shutter speed, it does what it wants and is useless for LPR.

Most PTZ cameras by the way are not suitable either because you cannot manually set a focus, so even if you can truly set a shutter speed, it cannot focus. Some people have had success by not using it as a PTZ and forcing it to B/W 24/7, but it is iffy on success.

 

[Bitslizer]

sorry, I didn't mean to run color at night, just that the color lux rating is often one of the metrics I can actually get my hands on for these budget PTZ to get a sense of the low light performance (0 lux with IR on doesn't help )

For the options I'm researching, the IR "supposedly" will reach 60-100m (200-300+ ft) which should be enough for how I think i will aim the cameras.

So we know a z12e with 0.002lux is capable of good result at 1/2000 BW with IR. what about a budget PTZ with 0.01lux...? would it still be get the 1/2000 BW/IR with good result?

Attached is a mock up with the IPVM Calc, ignore the dahua PTZ as that's just a similarly spec (1080p, 94mm) camera I can use for reference purpose
The north camera will be about 140ft max and with 94mm of reach it should stay in the 180-260 PPF range
The south camera will have 2 ROI (along the same aim line), first one at about 150ft, again should be about 200PPF, then there's a "bonus" ROI at about 220ft. Angle is fairly lousy (>45) and PPF will be only around 120ish but this second ROI is more, nice to be able to get it but not a must have.

To stay safe, I'll be buying with Amazon Prime, so I always have the free return option if they turn out to be junk. I more don't want to spend the time to mount them on a ladder (and drill holes into my new house) and have to take them down later.

 

[wittaj]

Rated IR is usually under ideal conditions with auto shutter, etc. Most folks in reality see half of what the IR says.

Since we are using it for LPR, it is an unique use case and is bouncing off of reflective plates, so the LUX rating isn't as critical (within reason).

Which budget PTZ are you looking at? Again, let the users here that have experience with specific cameras let you know...for example I know a Sunba will not work for this (I have one and have tried it at night and will not work)...or a JideTech as people have tried those and didn't work...The budget PTZs will not let you set a shutter speed or ignores it to give you a bright image...

As I mentioned, most PTZ cameras by the way are not suitable either for LPR because you cannot manually set a focus, so even if you can truly set a shutter speed, it cannot force a focus and the focus always changes based on what the image sees and with the image black at night, it may be useless.

Some people have had success by not using it as a PTZ and forcing it to B/W 24/7, but it is iffy on success. Some of the Dahua and Amcrest PTZs have the ability to semi-auto or manual the focus, but that has to be done right then and there - if you move the PTZ and then move back, it will not be in focus. But at that point, you are above the cost of the Z12....

Remember, at night, the image will be completely black except for the head/tail lights and the plate, so most PTZs at that fast shutter will not have anything to focus on and then when a car goes by, it will be blurry...

If you cannot truly set shutter and focus and the other parameters, then it doesn't matter what the LUX specs say...but if it lets you set shutter but then the software automatically ups the gain to 100% and you cannot change it, it will be useless as well...that is the problem with many budget cameras is the inability to force settings as they have wrote the firmware to adjust other parameters in an attempt to give a bright image, but then motion goes to crap. The inability to be able to truly set parameters will fail for LPR...

You can go down this rabbit hole and maybe get lucky, but why not use the experience of folks here?

But really, if you mention the PTZ you are looking at, someone here may have one and be willing to give it a try at night and see if it can work to see plates....

 

[Bitslizer]

Primarily these 2 to starts

Amazon.com : LEFTEK Star Light Camera Mini POE 1080P 18x Zoom IR High Speed Dome Camera Night Vision 196ft IR Distance Built in RJ45 Onvif Protocol : Camera & Photo

Amazon.com : LEFTEK Star Light Camera Mini POE 1080P 18x Zoom IR High Speed Dome Camera Night Vision 196ft IR Distance Built in RJ45 Onvif Protocol : Camera & Photo

www.amazon.com

https://www.amazon.com/Security-Outdoor-Tracking-Two-Way-Android/dp/B08Q44Z2V9

Of that 2, I'm leaning the Leftek even though it is more expensive. Leftek also have another 2 option at higher price

I have a POE wires to the existing locations and can use a PFT1300 type to split the POE and I have POE+ switch capable of pushing 30w and 60w to a single port if needed.

The cheap cube POE Revotech I picked up with 22mm to test/play with was enough to, in daylight, capture plate at about 45 degree angle (The north cam). But its got no IR unless I want to mod it and more zoom would be nice and allow both north and south cam to be within 30 degree horizontal

 

[wittaj]

So the LEFTEK looks like it is a Sunba camera (you will find that most cameras are made by only a few manufacturers and are rebadged as another brand), so I doubt that would work.

The XMARTO has some reviews with pictures and under "ideal" conditions being within a few feet of the camera, someone posted this picture and said "The picture quality is good" ...um if that is good then my eyes are bad LOL. If it cannot give a better picture that close of someone walking up steps, it will certainly fail as a license plate camera and a fast moving car.

I would be shocked if a budget cam will be able to be used for plate purposes at night simply due to the focus issue. If the Dahua and Hik PTZs do not allow a manual set of a focus like they do their fixed cams, I do not think a budget PTZ will provide it.

 

[Bitslizer]

I saw that and was wondering if it's a NR shutter speed issue.

The leftek I was researching for pictures and videos with sunba but I think the web ui look totally different? See video below and skip to 2:35

 

[wittaj]

What you will notice is that Sunba has several PTZs and the web gui is different for every one of them. One of their models looks like that, but I cannot recall which one but I think it was their autotrack model.

 

[Bitslizer]

What you will notice is that Sunba has several PTZs and the web gui is different for every one of them. One of their models looks like that, but I cannot recall which one but I think it was their autotrack model.

I see, thanks!

 

[Bitslizer]

@wittaj tinkering with focus. Any idea why the headlight is in focus and sharp but the plate is a blur? 1/2000 shutter if the camera aren't cheating. It is rainy tonight so not sure if wet plate has anything to do with it. Got an offer I couldn't refuse. Even if this don't work for lpr I still have an extra high zoom ptz to play with

 

[wittaj]

Wow - it looks like that plate was intentionally blurred out.

Does the camera have a backlight HLC you can turn on? Or drop the gain down?

What camera is this?

 

[Bitslizer]

Supposedly this guy... I managed to get a big coupon.

https://www.amazon.com/dp/B07BQY5NV...abc_EBXBJM97FXPMN0AQVSXK?_encoding=UTF8&psc=1

I had some funky issue with the dahua nvr can time sync crashing the stream (not the cam, just the stream) that took me forever to find out the cause she figure out how to stop the nvr from updating the clock of the camera by the time I got that sorted was too late to test the daylight but I don't recall the plate being blur during the day.

It has a back light but not a hlc. I have wdr turned off and 3dnr set low

 

[wittaj]

Yeah, like I mentioned, I am fairly confident it is a re-branded Sunba.

Try it with WDR turned on. I doubt that will do it, but it is worth a shot.

Maybe drop brightness down and contrast up as well.

I suspect the software is doing something funky, but that is closer than most of these cams get to this.

 

[Bitslizer]

Yeah, like I mentioned, I am fairly confident it is a re-branded Sunba.

Try it with WDR turned on. I doubt that will do it, but it is worth a shot.

Maybe drop brightness down and contrast up as well.

I suspect the software is doing something funky, but that is closer than most of these cams get to this.

Maybe It was the IR "hilightcompress" I had it max out.... Waiting for another car to pass by. I'm thinking to toy with python/onvif command on my raspberry pi to deal with the autofocus. I think I can set it to manual focus, just wonder if there's an absolute focus value I can preset

 

[wittaj]

Yeah, that may do it. Hopefully you can find a combination to make it work!

I have a cheapo cam that claims to allow me to adjust all these settings, but at the end of the day, the lil thing still does what it wants to. But it is an overview cam and not critical, but it does at least get me color of cars that I can then use to match up to my better cameras that are getting the vehicle in B/W.

 

[Bitslizer]

so leftek is a rebadge jidetek or they use the same oem... Supposed to work with hikvision protocol, I will see if their api works....

 

[Bitslizer]

For what it is worth for future reference. The leftek would not go into manual focus mode via onvif command nor would it let me set the focus near/far limit. It would accept those command but just doesn't do anything. Have not tried hikvision ISAPI yet.

Found a thread advising about parking my car to make it easier to dial in the night setting + reflective tape to help it keep focus. So far It seem to be able to keep focus if I adjust the automatic night mode to enter black and white early enough. I just need to dial in the exposure setting to be read the license plate.

 

[Bitslizer]

So I parked my car with it on... seems my exposure was already workable, but it was a focus issue. Weirdly it seems the focus for the pavement to be in focus is not the same as the focus for the plate... after i tuned the focus drove past seveal time back and forth upto 30mph and was able to get legible plates.

I do happen to have a city light pole where I plan to aim the camera. going to stick some reflective tape on it to see if it reflect the IR and help with focusing. If even that doesn't help then it won't work with LPR at night.

 

[wittaj]

Sweet - can't wait to see some photos. And yes what you will notice is that when you zoom in as tight/close as we do for LPR, the focus becomes critical and it is key to focus it where the plate will be. Auto focus may pick up the hydrant or mailbox or curb or light and that can be just enough difference that you don't get the plate.

 

[Bitslizer]

Sweet - can't wait to see some photos. And yes what you will notice is that when you zoom in as tight/close as we do for LPR, the focus becomes critical and it is key to focus it where the plate will be. Auto focus may pick up the hydrant or mailbox or curb or light and that can be just enough difference that you don't get the plate.

Day light and night when it's in focus. The night photo is moving at 30mph. Day light have the same exposure setting.

I stuck some reflective tape on the light pole but it's still bright out... See what happens once it's fully dark