Vantrue N4S review

[TonyM]

I'm comparing my 4K Viofo A229 Pro (3840 x 2160P 4K) to the Vantrue N4S (2560 x 1440P Quad HD). It's not a truly fair comparison since they use different image sensors and resolutions but I was surprised how close they looked. I was traveling at 38 MPH. Neither camera could read the oncoming traffic plates but both could make out the street sign on the right.

Why are both modern STARVIS 2 cameras struggling to read a number plate in daylight at under 40mph?

I think there's a loss of detail due to compression artefacts which affects both videos.

Did you check the number plates a few frames earlier? The truck in the A229 Pro video in particular looks sharper at the back end than the front end.

 

[Hack_man]

Why are both modern STARVIS 2 cameras struggling to read a number plate in daylight at under 40mph?

I think there's a loss of detail due to compression artefacts which affects both videos.

Did you check the number plates a few frames earlier? The truck in the A229 Pro video in particular looks sharper at the back end than the front end.

Good question, I didn't give it much thought since both cameras looked similar.
I checked a few frames earlier and both cameras could not read the plates on the blue truck.
This blurry behavior repeated on all the cars until I slowed down to about 25 MPH when the plates came into view better but not great on both cameras. This is surprising.
There does seem to be more motion blur on the N4S when you look at the" Lincoln Hall Parking" sign

N4S 26 MPH Resolution = 1440P

A229 Pro 26 MPH Resolution = 2160P

 

[TonyM]

Have you checked sharpness across the frame on a static scene? The screenshots in post #12 look good but you have covered the left edge with the video data.

Do you have PlatePix turned on for the N4S? If not, this should help for the subjects you are trying to capture.

 

[Hack_man]

Here is the same static scene from post #12 without the video data on the left edge.
I think the sharpness looks decent across the frame on both cameras. I don't believe PlatePix is turned on for the N4S. I wish Vantrue gave that info on the image like VIOFO does for HDR enabled. (EDIT: Vantrue DOES show PlatePix enabled on the video file ).
I will enable PlatePix moving forward.
I seem to remember looking at previous footage on the A229 Pro where plates were very readable when approaching at 40 MPH.

 

[TonyM]

I don't believe PlatePix is turned on for the N4S. I wish Vantrue gave that info on the image like VIOFO does for HDR enabled.

I don't have an N4S, but on my other Vantrue cameras the user can choose what appears in the 'stamp' on screen display, and PlatePix is shown if it is active.

I see @EricSan has the PlatePix text showing on his video

 

[Hack_man]

Based on the N4S user manual, they recommend PlatePix be disabled during low light conditions , but the image they show with PlatePix enabled is at night so this is a bit confusing.
The image in the manual looks like a Low light condition and PlatePix enhanced the license plate text. What am I misunderstanding?

 

[EricSan]

I'll see if I can make a few night time videos tonight and compare PlatePix and HDR settings. Now that it's nearly solstice in the northern hemisphere, I have to wait a bit longer for it get dark...

 

[haiou_f]

Here is the same static scene from post #12 without the video data on the left edge.
I think the sharpness looks decent across the frame on both cameras. I don't believe PlatePix is turned on for the N4S. I wish Vantrue gave that info on the image like VIOFO does for HDR enabled.
I will enable PlatePix moving forward.
I seem to remember looking at previous footage on the A229 Pro where plates were very readable when approaching at 40 MPH.

View attachment 81561

View attachment 81558

From this comparison chart, it can be seen that due to the influence of resolution, the clarity of the n4s during the day is relatively poor compared to the a229Pro。

 

[Hack_man]

I don't have an N4S, but on my other Vantrue cameras the user can choose what appears in the 'stamp' on screen display, and PlatePix is shown if it is active.

I see @EricSan has the PlatePix text showing on his video
View attachment 81578

There is no choice in "stamp" for PlatePix but "PlatePix" does automatically appear when enabled.
"HDR" is NOT shown on the video file. I think this should be corrected and HDR should be displayed.

 

[Hack_man]

Nighttime footage comparing A229 Pro and N4S
I want to repeat this with PlatePix turned OFF next time. The N4S is struggling a bit.
The PlatePix timer and HDR timer are tied together so that whatever I set the HDR timer, the PlatePix timer synchronizes with it. According to Vantrue this is expected behavior.
I'm not sure what is the point of the PlatePix timer if its just going to mimic the HDR timer settings

N4S HDR ON

 

[TonyM]

There is no choice in "stamp" for PlatePix but "PlatePix" does automatically appear when enabled.
"HDR" is NOT shown on the video file. I think this should be corrected and HDR should be displayed.

I agree it would be nice to see when HDR is active or not, although that's probably more interesting to us here in DCT than the average user.

 

[haiou_f]

I think the n4s and a119mini2 are more comparable。

 

[Hack_man]

PlatePix was turned OFF in this image with HDR ON.
I'm going to try to get another nigh time picture with a car directly in front with PlatePix turned ON but from what I am seeing here nighttime video needs PlatePix

 

[Hack_man]

PlatePix was turned ON
I think the N4S is doing a better job displaying the plate in front of me than the A229 Pro.
The screenshot for the VIOFO I view on my computer looks better than what I can post on this forum, I can more clearly read the white sign above the car in front of me with the A229 Pro but not with the S1 PRO Max
There is some compression going on when uploading the screenshot file to Dashcamtalk that I hadn't noticed before.

So bottom line is PlatePix really does seem optimized for reading plates but less so for other types of text which are not block letters.

N4S HDR ON PLATEPIX ON

A229 Pro HR ON

N4S

A229 Pro

 

[Hack_man]

This post is not directly related to the N4S but to the "Vantrue Hardwire Kit for Dash Cam"
I wanted to confirm the accuracy of the low voltage trip points which turns the camera off when the battery drops below a threshold voltage during parking mode to protect the battery.
The Vantrue Hardwire Kit only has two voltage settings, 12.0 and 11.6 Volts.

I tested both voltages and the camera powered off within 0.1 volts of dropping below the voltage settings. My Fluke 73 III has not been recently calibrated, but the results make sense.
First I powered up the camera by supplying the Hardwire kit with 13.5 V at the Battery and Accessory terminals.
I disconnected the Accessory (Yellow Wire) from the power supply to enter parking mode, and then slowly reduced the power supply voltage.
The trip points are a little hard to find, since there is a very long time delay before the circuit trips (on the order of 5 minutes).
I am wondering if camera current draw impacts turn off delay time, which implies different cameras and channel configurations might change the time delay.

I used a Vantrue E360 for test purposes rather than the N4S.
Conclusion: The Hardwire kit works but there is a longer turn off time delay than I expected.

 

[EricSan]

I found similar results when I powered the hard wire kits with my bench power supply. I started at voltage levels above the cutoff values on the switch and then decreased the voltages step by step over a long period of time. It seems to take the regulator more than 2-3 mins (maybe longer) to shut down the camera once the voltage threshold is reached. I found the shut-down setting to be accurate to about 0.03v or so, so they're pretty spot on. The part that surprised me was the time delay between when the voltage threshold is reached and when the output voltage turns off. It took me a while to figure this out and I ended up adjusting the input to the regulator, then wandering off to do other things and checking back every few minutes to see if the camera was still powered on.

My conclusion is very similar to yours: The switch settings are very accurate, but it takes a few minutes to turn things off. This seems fine, given the capacity of a car battery - a few minutes here or there won't create or solve a problem.

 

[Hack_man]

I'm guessing that the comparator circuitry is driven with a large RC time constant so that glitches don't cause the camera to turn off accidentally. Like @EricSan said, there really is no reason to respond instantaneously to spikes on the supply line.
The comparator likely drives a control signal on the regulator, probably a voltage follower OP Amp driving the RC time constant.
We just have to open up this Hardwire kit!