License plate concern: 1080p@30fps vs 1080p@60fps

[Hieu Vu]

Hi guys,

As the title may have suggested, I want my dashcam to be able to capture license plates easily. So, the question is do I need the resolution to be at 1080p@60fps, or 1080p@30fps is already enough?
And thus, could I have some recommendations of dashcams meeting this requirement of reading license plates with ease please? Budget is not really a concern. Having a screen is a plus since I will be able to see the footage as soon as any incident happens.

Thanks in advance

 

[jokiin]

no camera will catch every licence plate all the time, 60fps is no guarantee of improved results over and above 30fps either

 

[kamkar]

No please dont get too focused on reading license plates, if you do then you will be disappointed with any camera you get.
It dont take too much outside perfect conditions before reading plates on oncoming cars get problematic, thats just the way it is with current hardware in use.

What current dashcams do more or less perfect all the time is record what you do with your car, and if you do nothing wrong then if something happen it must be blamed on some one else, and his crashed or dented car will probably be right there next to yours, unless off course he run from the scene of the accident.

I too prefer 1080/60 but having used that beside 1080/30 cameras i cant really say it make much difference in plate capture, the difference between the 2 is marginal i think.

What i have found is having a camera with a modified lens on it ( 8 mm ) do sort of increase plate capture, but as a 8 mm lens is narrow FOV then i can not recommend using such camera alone, it must be paired with a wide angle camera.
But the narrow 8 mm lens mean i can read plates longer about 2 X longer ahead of my car than a wide angle camera, and it is to me as if this work better in low light conditions ( not darkness just low light as on a grey rainy day )

 

[kamkar]

Let me elaborate a little more on this.

Lets say you have 2 similar cameras and run one with 1080/60 and the other with 1080/30 settings and then go for a drive, then i am pretty sure most the plates the 1080/60 camera capture so will the 1080/30 camera.
Lets say your test drive is with 100 events that have a 100% capture on the 1080/60 camera, then the numbers with the 1080/30 camera should be up there too, maybe 98% or 95% at the very worst.
So the difference in captured plates is little, and it will not be like those plates the 1080/60 camera got and the other dident that the 1080/60 plates will be razor sharp captures and the 1080/30 ones will just be a blur.
From my own testing i have come to see that in many cases it take some guesswork to figure out the plate, and i have to verify that against our national plate register to make sure the plate and car model/color match what i can read on the plate.

You can get razor sharp plate captures on a Danish highway with cars passing right past each other at 80 km/h, but then its optimal lighting conditions and you will see several frames in row in the footage with the plate number.
But on bad days, then you will only have 1 chance where you might be able to read or guess the plate on that other car, and thats just the way it is with current technology in use.

In my own testing with 1080/60 Vs 1080/30 cameras ( not same sensors ) is it is damn rare the 60 FPS camera get a capture and the other one dont.

But what i do think is.

With future cameras with even more light sensitive sensors, those run with the 1080/60 setting should start to edge ahead of current sensors with 1080/30.
And they should do that due to the more light sensitive sensors will allow for those cameras to use a faster exposure, but at peak hours of day with optimal light conditions, but also as the light start to fade.
But i am also sure in the dead of night on a dark highway, or for that matter in a town with plenty of lit up billboards and lots of ambient light, then the new sensors will still struggle as they are by no means light sensitive enough for it to have a usable effect on dark roads.

But what i foresee now with my current knowledge is the new up coming sensors will not be a game changer at least not in regard to plate capture, they will be better and surely worth buying if you have no or just a old dashcam.
But if you have a current good camera, you really have to think if it is worth the upgrade if money is tight for you.
Off course if you are a dashcam addicted person than its a no brainer, get a new camera ASAP but i just hope for those people they haven't gotten too exited, cuz then i think they might be disappointed with their new camera.

What i recommend you look for is a camera that first of all can handle the Vietnamese weather conditions, And then look at what features those cameras have you can use and which ones you might have to do without.

 

[niko]

Too many things affecting plates reading.

If you have two daschams which are based on same hardware, have same lens, firmware comes from same developer, then 1080p/60 will be slightly better but not marginally and it's only in a good daytime weather condition ( sunny day ), however at night 30fps usually performs better than 60fps.

You can get 1080p / 30fps with high quality lens which will outperform 1080p/60fps even at daytime. All depends on hardware (mainly processor) used, how well is firmware tuned up, how good are lens, what FOV are lens etc. The narrower lens will bring objects closer but drawback is more motion blur when vehicle is bypassing you. Too wide FOV lens are also not the best for reading bypassing cars due to less focus at the edges. Best result you may see from medium-FOV lens. But again, even if you get dascham with best possible combinations of hardware / firmware, there is still outside factors which affects license plates reading, like speed, weather, shadows etc.

For example some daschams may capture license plates at 120 km/h from towards moving cars ( total 240 km/h ) in perfect conditions, but at the same time same dascham may not capture plates at much lower speeds if light conditions are not good enough for that.

 

[kamkar]

It is paramount dashcams do not start to drop to slower exposure timings before it is needed really bad, i have a sneaky feeling some zig-zag up thru ISO values and down thru slower exposure timings, and this is creating dashcams that get different results. ( and vise versa going into light )

I am not quite sure how these only 2 "knobs" you can adjust on in dash and action cameras is linked together is they are that at all, but my feeling tell me if the 2 dont work in the right way together then unfortunate results can occur in the footage.

 

[Hieu Vu]

Thanks guys for your replies.

Let me elaborate a little more on this.

Lets say you have 2 similar cameras and run one with 1080/60 and the other with 1080/30 settings and then go for a drive, then i am pretty sure most the plates the 1080/60 camera capture so will the 1080/30 camera.
Lets say your test drive is with 100 events that have a 100% capture on the 1080/60 camera, then the numbers with the 1080/30 camera should be up there too, maybe 98% or 95% at the very worst.
So the difference in captured plates is little, and it will not be like those plates the 1080/60 camera got and the other dident that the 1080/60 plates will be razor sharp captures and the 1080/30 ones will just be a blur.
From my own testing i have come to see that in many cases it take some guesswork to figure out the plate, and i have to verify that against our national plate register to make sure the plate and car model/color match what i can read on the plate.

You can get razor sharp plate captures on a Danish highway with cars passing right past each other at 80 km/h, but then its optimal lighting conditions and you will see several frames in row in the footage with the plate number.
But on bad days, then you will only have 1 chance where you might be able to read or guess the plate on that other car, and thats just the way it is with current technology in use.

In my own testing with 1080/60 Vs 1080/30 cameras ( not same sensors ) is it is damn rare the 60 FPS camera get a capture and the other one dont.

But what i do think is.

With future cameras with even more light sensitive sensors, those run with the 1080/60 setting should start to edge ahead of current sensors with 1080/30.
And they should do that due to the more light sensitive sensors will allow for those cameras to use a faster exposure, but at peak hours of day with optimal light conditions, but also as the light start to fade.
But i am also sure in the dead of night on a dark highway, or for that matter in a town with plenty of lit up billboards and lots of ambient light, then the new sensors will still struggle as they are by no means light sensitive enough for it to have a usable effect on dark roads.

But what i foresee now with my current knowledge is the new up coming sensors will not be a game changer at least not in regard to plate capture, they will be better and surely worth buying if you have no or just a old dashcam.
But if you have a current good camera, you really have to think if it is worth the upgrade if money is tight for you.
Off course if you are a dashcam addicted person than its a no brainer, get a new camera ASAP but i just hope for those people they haven't gotten too exited, cuz then i think they might be disappointed with their new camera.

What i recommend you look for is a camera that first of all can handle the Vietnamese weather conditions, And then look at what features those cameras have you can use and which ones you might have to do without.

I do understand that we can't have license plates captured every single time, I just want to know what is the best option we have right now. From your answer, is it ok for me to summarise it as: "get 2 dashcams, 1 with wide FOV to capture the whole scene and 1 with narrow FOV to capture the license plate better" ?
I don' think I will need many features. Just the usual parking mode, and auto start with vehicle (or motion detection) is enough I guess.

Too many things affecting plates reading.

If you have two daschams which are based on same hardware, have same lens, firmware comes from same developer, then 1080p/60 will be slightly better but not marginally and it's only in a good daytime weather condition ( sunny day ), however at night 30fps usually performs better than 60fps.

You can get 1080p / 30fps with high quality lens which will outperform 1080p/60fps even at daytime. All depends on hardware (mainly processor) used, how well is firmware tuned up, how good are lens, what FOV are lens etc. The narrower lens will bring objects closer but drawback is more motion blur when vehicle is bypassing you. Too wide FOV lens are also not the best for reading bypassing cars due to less focus at the edges. Best result you may see from medium-FOV lens. But again, even if you get dascham with best possible combinations of hardware / firmware, there is still outside factors which affects license plates reading, like speed, weather, shadows etc.

For example some daschams may capture license plates at 120 km/h from towards moving cars ( total 240 km/h ) in perfect conditions, but at the same time same dascham may not capture plates at much lower speeds if light conditions are not good enough for that.

View attachment 27746

Can I ask why 30fps will perform better than 60fps at night? The traffic in my country will limit the speed to 60km/h, so with 2 vehicles from oppposite directions it would only add up to 120km/h. Should not be a big deal right?

 

[jokiin]

Thanks guys for your replies.



I do understand that we can't have license plates captured every single time, I just want to know what is the best option we have right now. From your answer, is it ok for me to summarise it as: "get 2 dashcams, 1 with wide FOV to capture the whole scene and 1 with narrow FOV to capture the license plate better" ?
I don' think I will need many features. Just the usual parking mode, and auto start with vehicle (or motion detection) is enough I guess.



Can I ask why 30fps will perform better than 60fps at night? The traffic in my country will limit the speed to 60km/h, so with 2 vehicles from oppposite directions it would only add up to 120km/h. Should not be a big deal right?

you won't catch plates at night going in opposite directions, there is way too much motion blur in low light

 

[niko]

Thanks guys for your replies.



I do understand that we can't have license plates captured every single time, I just want to know what is the best option we have right now. From your answer, is it ok for me to summarise it as: "get 2 dashcams, 1 with wide FOV to capture the whole scene and 1 with narrow FOV to capture the license plate better" ?
I don' think I will need many features. Just the usual parking mode, and auto start with vehicle (or motion detection) is enough I guess.



Can I ask why 30fps will perform better than 60fps at night? The traffic in my country will limit the speed to 60km/h, so with 2 vehicles from oppposite directions it would only add up to 120km/h. Should not be a big deal right?

Its due to Exposure Value. 60Fps at night captures less light per 1 sec vs 30Fps per 1sec. Also depends on ISO and CMOS sensor used.

Sent from my LG-H962 using Tapatalk

 

[Hieu Vu]

Let me elaborate a little more on this.

Lets say you have 2 similar cameras and run one with 1080/60 and the other with 1080/30 settings and then go for a drive, then i am pretty sure most the plates the 1080/60 camera capture so will the 1080/30 camera.
Lets say your test drive is with 100 events that have a 100% capture on the 1080/60 camera, then the numbers with the 1080/30 camera should be up there too, maybe 98% or 95% at the very worst.
So the difference in captured plates is little, and it will not be like those plates the 1080/60 camera got and the other dident that the 1080/60 plates will be razor sharp captures and the 1080/30 ones will just be a blur.
From my own testing i have come to see that in many cases it take some guesswork to figure out the plate, and i have to verify that against our national plate register to make sure the plate and car model/color match what i can read on the plate.

You can get razor sharp plate captures on a Danish highway with cars passing right past each other at 80 km/h, but then its optimal lighting conditions and you will see several frames in row in the footage with the plate number.
But on bad days, then you will only have 1 chance where you might be able to read or guess the plate on that other car, and thats just the way it is with current technology in use.

In my own testing with 1080/60 Vs 1080/30 cameras ( not same sensors ) is it is damn rare the 60 FPS camera get a capture and the other one dont.

But what i do think is.

With future cameras with even more light sensitive sensors, those run with the 1080/60 setting should start to edge ahead of current sensors with 1080/30.
And they should do that due to the more light sensitive sensors will allow for those cameras to use a faster exposure, but at peak hours of day with optimal light conditions, but also as the light start to fade.
But i am also sure in the dead of night on a dark highway, or for that matter in a town with plenty of lit up billboards and lots of ambient light, then the new sensors will still struggle as they are by no means light sensitive enough for it to have a usable effect on dark roads.

But what i foresee now with my current knowledge is the new up coming sensors will not be a game changer at least not in regard to plate capture, they will be better and surely worth buying if you have no or just a old dashcam.
But if you have a current good camera, you really have to think if it is worth the upgrade if money is tight for you.
Off course if you are a dashcam addicted person than its a no brainer, get a new camera ASAP but i just hope for those people they haven't gotten too exited, cuz then i think they might be disappointed with their new camera.

What i recommend you look for is a camera that first of all can handle the Vietnamese weather conditions, And then look at what features those cameras have you can use and which ones you might have to do without.

Btw, I'm using Mobius on my helmet when I'm motorcycling. Currently, there's no dashcam installed in my car. The traffic in my country is pretty bizarre with countless of motorbikes swarming, so most of the time I will ride my bike. I will only drive the car when it's raining or it's a very hot day. And no I'm not a dashcam addicted person, I just want something that fits my requirement

 

[Hieu Vu]

Its due to Exposure Value. 60Fps at night captures less light per 1 sec vs 30Fps per 1sec. Also depends on ISO and CMOS sensor used.

Sent from my LG-H962 using Tapatalk

thanks for the info. I guess I will stick with 30fps then

 

[Hieu Vu]

Its due to Exposure Value. 60Fps at night captures less light per 1 sec vs 30Fps per 1sec. Also depends on ISO and CMOS sensor used.

Sent from my LG-H962 using Tapatalk

And may I ask what's the best dashcam for night video quality right now? SG9665GC? SGZC12RC?

 

[niko]

thanks for the info. I guess I will stick with 30fps then

Your Mobius is a good choice to be used in car as well. Just buy or make quick release permanent mount plus hardwiring or cigarette lighter charger.

Sent from my LG-H962 using Tapatalk

 

[niko]

And may I ask what's the best dashcam for night video quality right now? SG9665GC? SGZC12RC?

SG9665GC has almost no background noise， black is black. SGZC12RC advantage is remore lens，which is more flexible for different mounting solutions like side / doors / rear. At night overall performance is almost the same on both of them but for your eyes SG9665GC looks better， however non of them will capture number plates from moving vehicles if speeds difference is over 10km/h(+/-) if we talk about streets with no or very little lights.

Sent from my LG-H962 using Tapatalk

 

[Hieu Vu]

Your Mobius is a good choice to be used in car as well. Just buy or make quick release permanent mount plus hardwiring or cigarette lighter charger.

Sent from my LG-H962 using Tapatalk

SG9665GC has almost no background noise， black is black. SGZC12RC advantage is remore lens，which is more flexible for different mounting solutions like side / doors / rear. At night overall performance is almost the same on both of them but for your eyes SG9665GC looks better， however non of them will capture number plates from moving vehicles if speeds difference is over 10km/h(+/-) if we talk about streets with no or very little lights.

Sent from my LG-H962 using Tapatalk

I do know that Mobius is still a decent choice even now, however, I do want to keep Mobius on my helmet for my motorbike use, and more importantly, I want to step it up on dashcams on my car. I'm thinking of SG9665GC as a front cam, SGZC12RC as a rear cam, just wondering if they are already the best options for night quality at the moment?

 

[kamkar]

You cant get dashcams with a that narrow lens, so you will have to make a lens swap yourself.
But if you can look past plate capture as important then we can move on, besides that narrow lens is not a fix its just something i feel help a little bit.

The reason that 30 fps cams cam be better than 60 FPS cameras at night is due to the fack that with 30 fps you can have double as long time for eash frame exposure than with 60 FPS footage.
But the problem is with so slow exposure timings and things in the footage moving then you will get motion blur as a thing in the footage is moving while each frame is taken.
If only things wasent moving then we could expect bright and crisp pictures in darkness, just like this picture i tool lately with my Dslr camera.

It took the camera 20 seconds to take this picture, so if there had been just a little movement then those moving parts would have been blurred.
But there was little wind this night, so the tree on the right in the footage is defined, had it been a little windy then the outline of the treetop would have been severe blurred as those branches would have been moving as the picture was taken.

But thats not the case with dashcam footage where things move pretty darn fast, and low light and movement is not good.

For dashcams to perform optimal they should use exposure timings over 1/500 second all the time, but not even professional cameras can do that as they too are not light sensitive enough.
So cameras can up the ISO value, but problem is going too far with ISO value make footage noisy and look bad.

So even just you driving at 60 km/h then things off to the side of the footage will be a blur as they move XX cm while every frame is exposed, if you was driving at walking speed than it would be a lot better.

If you notice commercial footage from most dashcam brands you will see nice fairly crisp night footage, but if you pause and think about you will notice that the footage is recorded in a town with a lot of light, and the traffic where the footage is filmed is probably also slow moving.

And trust me even with the best dashcams on the market low light is a major issue ( the biggest challenge for all making dashcams )
And sadly it dont even have to be night time low light, up here in Denmark this time of the year i can barely get a plate capture on a 80 km/h highway, like yesterday i might be lucky the sun is out, but this time of the year it dont get high over the horizon so the flat angle of the light is a issue too.

As it is now over the total of a whole day, then plate capture is a game of chance, not anything to rely on for sure, thats also why the recommendation from us in here is that if something happen at night, see the plate yourself and call out the numbers for the camera microphone to record, do not count on the camera to do that.

 

[kamkar]

There is new cameras on the way, they will have the Sony IMX 291 sensor that is better in low light than the IMX 322 used in current top low light performers like the SG9665GC.
There is many cameras with the IMX322 sensor out there, but some / many of those have other parts thats cheap so its a big question if they would survive a summer in Vietnam.

If you would like front and rear cameras in your car then SG and others too i assume have nice new products coming to the market soon, and some will have the IMX291 in the front camera and the "old" IMX 322 in the rear camera.

 

[Hieu Vu]

You cant get dashcams with a that narrow lens, so you will have to make a lens swap yourself.
But if you can look past plate capture as important then we can move on, besides that narrow lens is not a fix its just something i feel help a little bit.

The reason that 30 fps cams cam be better than 60 FPS cameras at night is due to the fack that with 30 fps you can have double as long time for eash frame exposure than with 60 FPS footage.
But the problem is with so slow exposure timings and things in the footage moving then you will get motion blur as a thing in the footage is moving while each frame is taken.
If only things wasent moving then we could expect bright and crisp pictures in darkness, just like this picture i tool lately with my Dslr camera.

It took the camera 20 seconds to take this picture, so if there had been just a little movement then those moving parts would have been blurred.
But there was little wind this night, so the tree on the right in the footage is defined, had it been a little windy then the outline of the treetop would have been severe blurred as those branches would have been moving as the picture was taken.

But thats not the case with dashcam footage where things move pretty darn fast, and low light and movement is not good.

For dashcams to perform optimal they should use exposure timings over 1/500 second all the time, but not even professional cameras can do that as they too are not light sensitive enough.
So cameras can up the ISO value, but problem is going too far with ISO value make footage noisy and look bad.

So even just you driving at 60 km/h then things off to the side of the footage will be a blur as they move XX cm while every frame is exposed, if you was driving at walking speed than it would be a lot better.

If you notice commercial footage from most dashcam brands you will see nice fairly crisp night footage, but if you pause and think about you will notice that the footage is recorded in a town with a lot of light, and the traffic where the footage is filmed is probably also slow moving.

And trust me even with the best dashcams on the market low light is a major issue ( the biggest challenge for all making dashcams )
And sadly it dont even have to be night time low light, up here in Denmark this time of the year i can barely get a plate capture on a 80 km/h highway, like yesterday i might be lucky the sun is out, but this time of the year it dont get high over the horizon so the flat angle of the light is a issue too.

As it is now over the total of a whole day, then plate capture is a game of chance, not anything to rely on for sure, thats also why the recommendation from us in here is that if something happen at night, see the plate yourself and call out the numbers for the camera microphone to record, do not count on the camera to do that.

thanks alot for your detailed explanation. Mobius does have the option of narrowing the FOV afaik btw. I will certainly call out the plate number if I have the chance, but in the case of the incident happening too fast and the other car/motorbike hit and run then I really hope the dashcam can help me on the plate. But I guess the technology now can't help us much

 

[Hieu Vu]

There is new cameras on the way, they will have the Sony IMX 291 sensor that is better in low light than the IMX 322 used in current top low light performers like the SG9665GC.
There is many cameras with the IMX322 sensor out there, but some / many of those have other parts thats cheap so its a big question if they would survive a summer in Vietnam.

If you would like front and rear cameras in your car then SG and others too i assume have nice new products coming to the market soon, and some will have the IMX291 in the front camera and the "old" IMX 322 in the rear camera.

We have up to 50 Celcius degree here in summer @@ thanks for your info on the new upcoming cameras. I guess I will wait to see if the new IMX 291 really step it up compared to IMX 322. Apart from the sensor used, can I ask what are the factors making SG9665GC the top when compared to other IMX 322 cameras?

 

[kamkar]

Yes on some cameras you can get a narrow FOV by using just the middle of the sensor, but i think it would be better to do it with the optics in the lens and then use the whole sensor to capture the image.

Yes it is sad the technology is not quite where it should be, there are other larger and much more light sensitive sensors on the market, but then dashcams would be like 4- 5 X larger and the prize 10 - 15 X larger too.
So those that make dashcams have to strike a balance between what is best for the footage and what price they can sell the product for.

While hit and run is on the up here in Denmark, and traffic have not reached the levels as seen in Vietnam, and i have fait in my cameras and my insurance company.
And night or day the current dashcams document 100% good all the time is that what i do with my car is not illegal, so if anything happen that my cameras dont capture well then at least i can document that i was driving like a should be, and not like the other guy lie about me being all over the road or running a red light, or what ever people will lie about to make them self look better.

So we can prove we are good drivers and done do wrong, and the stupid the other drivers do if we capture it its okay to put them in jail or take their licence avay from them.
Or if its just regular stupid traffic put it on youtube so the world can laugh at them.

This summer i captured this guy, and from what i know of Danish traffic law he should not be driving for some years and will have to take driving test again before he is allowed to drive.

Driving on bicycle path and sidewalk and passing cars on the right side.

This is BTW filmed on the camera with the 8 mm lens