Licence plate readability, is this normal?

Karagandinez said:
You don't understand that 2160P is 4K, that is, 3840x2160P.
And if you look at the instructions, then in all four points there is a resolution: 3840x2160P
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You're right, I don't understand. Never mind, I'll just go back to sleep. LOL
 
cea5t said:
You're right, I don't understand. Never mind, I'll just go back to sleep. LOL
Click to expand...
Let’s dive into the fascinating world of 4K resolution and unravel the various naming techniques.

What Is 4K Resolution?

  • 4K resolution, also known as Ultra HD (UHD), refers to a display resolution with approximately 4,000 pixels horizontally. It’s like having four times the pixel power of your old-school 1080p resolution.
  • But here’s the quirky part: The industry decided to name it “4K” based on image width, not height. So, while 1080p was all about the vertical pixel count, 4K is all about the horizontal pixel count. Sneaky, sneaky!
  • Oh, and just to keep you on your toes, you might hear 4K resolution casually referred to as “2160p.”
Different 4K Resolutions:

  • 3840 × 2160 (4K UHD): This is the dominant 4K standard for television and consumer media. It’s like the rockstar of 4K—widely used, with a 16:9 aspect ratio.
  • 4096 × 2160 (DCI 4K): Now, this one struts its stuff in the movie projection industry. It’s slightly wider than the UHD version, with a 17:9 aspect ratio. Picture epic cinematic moments unfolding on the big screen.
 
And just to confirm my findings I found this post by @Dashmellow where he explains the effect a CPL filter has on a video. And it's exactly what I'm experiencing, on the cloudy overcast day or when it's getting darker.

"The second image was captured on the same road, also at 40+ miles per hour on an overcast day but with the CPL on the camera and you can see that the oncoming car is affected by motion blur."

Having a CPL filter is nice since it cuts down on the car's dash reflection and you can see better into other cars through the windows and helps with reflections on the road when it's raining etc. And it doesn't affect the recordings that much on a bright sunny day. But the downside of it is that it makes video blurry for upcoming traffic at higher speeds on overcast cloudy days which is most of the time here in Britain. So for me being able to see upcoming cars licence plates is more valuable then less reflection of my dash. So I think I will go with no CPL for my setup. There is more information on that thread on how CPL affects the image on how much light is blocked from entering the lens and how much it may affect your shutter speeds hence making images blurry on higher speeds etc. Have a look through the post if you are interested here.

Dashmellow said:
Here's a good example of the difference between having a CPL on your camera or not having one as far as motion blur is concerned.

One of my cameras is a Mobius 1S 2K cam with an 8mm 12 megapixel ƒ/1.8 telephoto lens on it. The camera is custom fitted with a unique 37mm HOYA HD polarizer. HOYA makes the finest polarizers available and this particular one transmits a full ƒstop more light to the sensor than any other CPL on the market except the even higher quality (and price) HOYA HD3 HRT polarizer they have come out with since. You can read more about the original HOYA HD polarizer I have on this camera HERE.

View attachment 66639

Anyway, here are several screen shots taken with the same camera on different cloudy overcast days. One image was taken without the polarizer yet clearly captures the plate number as the oncoming car and I approached each other at 40+ miles per hour.

The motion blur with this CPL which performs better than most is noticeable but usually tolerable. I can basically still make out the plate number but not quite so easily. However, you can certainly see the difference between having a CPL on the camera or not in overcast lighting.

Occasionally, with the CPL on the camera the motion blur can be much worse as seen in the third image. What is different in this image is that it is on hour later in the evening and actually darker out but the camera has compensated and so the image doesn't really reveal that.

All in all the superior performance of this CPL in most situations is the reason I went to the trouble of figuring out a way to mount a filter of this size on this particular camera but it is still a CPL and has the same drawbacks as any other.

No CPL
View attachment 66638

With CPL
View attachment 66637

View attachment 66640
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i got a CPL on the A810 now, also just gotten some driving in with pretty bleak weather, will whip video up and share later.
 
Paulbri said:
So for me being able to see upcoming cars licence plates is more valuable then less reflection of my dash. So I think I will go with no CPL for my setup.
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Having a CPL fitted will increase motion blur a little in some circumstances, such as around 6PM at this time of year, however it makes no real difference once it is dark, if you have HDR on, and no real difference in sunshine with HDR off. So for an A229 Pro, while you may want to remove it for the next month, you are probably better off with it on after that, until the spring. This does depend on your car, in some vehicles, they make little improvement anyway, while in others they are essential.

While looking at results with older cameras is informative, the results don’t necessarily apply with the latest cameras, so it is good for you to experiment with your own setup and decide for yourself. But do more than one test before deciding.
 
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Paulbri said:
And just to confirm my findings I found this post by @Dashmellow where he explains the effect a CPL filter has on a video. And it's exactly what I'm experiencing, on the cloudy overcast day or when it's getting darker.

"The second image was captured on the same road, also at 40+ miles per hour on an overcast day but with the CPL on the camera and you can see that the oncoming car is affected by motion blur."

Having a CPL filter is nice since it cuts down on the car's dash reflection and you can see better into other cars through the windows and helps with reflections on the road when it's raining etc. And it doesn't affect the recordings that much on a bright sunny day. But the downside of it is that it makes video blurry for upcoming traffic at higher speeds on overcast cloudy days which is most of the time here in Britain. So for me being able to see upcoming cars licence plates is more valuable then less reflection of my dash. So I think I will go with no CPL for my setup. There is more information on that thread on how CPL affects the image on how much light is blocked from entering the lens and how much it may affect your shutter speeds hence making images blurry on higher speeds etc. Have a look through the post if you are interested here.
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You can watch videos and screenshots with videos of the models I use.
On all models, except for the VS1, the CPL filter is not removed either during the day or at night.
How it is prepared: The result is visible to the naked eye.
 
Paulbri said:
So for me being able to see upcoming cars licence plates is more valuable then less reflection of my dash. So I think I will go with no CPL for my setup.
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A viable alternative to using a CPL that will effectively eliminate most windshield reflections without any of the increase in motion blur caused by the CPL (slower shutter speeds) is to use a black dash mat. These are available to custom fit many, if not most vehicles and increasingly so for right hand drive cars. (which hasn't always been the case)

You can see an example of how this works and learn more about dash mats in THIS post and there are other discussions on the forum about dash mats as well.

The question of using HDR at night to capture license plates is really a separate issue in my opinion as it doesn't address overcast weather during the day nor does it apply well to nations across the world that use smaller license plates.
 
Dashmellow said:
A viable alternative to using a CPL that will effectively eliminate most windshield reflections without any of the increase in motion blur caused by the CPL (slower shutter speeds) is to use a black dash mat. These are available to custom fit many, if not most vehicles and increasingly so for right hand drive cars. (which hasn't always been the case)

You can see an example of how this works and learn more about dash mats in THIS post and there are other discussions on the forum about dash mats as well.

The question of using HDR at night to capture license plates is really a separate issue in my opinion as it doesn't address overcast weather during the day nor does it apply well to nations across the world that use smaller license plates.
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I'll look into dash mats, thanks.
Is your opinion still that CPL makes blurry images for upcoming traffic on overcast days at speed or do you think it changed with the never A229 Pro cameras since your post I quoted was tested with the older camera as @Nigel pointed out? Also, what is your stans on HDR or not to HDR during the day? That is if you have any experience with the A229 Pro since different brands have different versions of HDR and might not compare.
 
Paulbri said:
I'll look into dash mats, thanks.
Is your opinion still that CPL makes blurry images for upcoming traffic on overcast days at speed or do you think it changed with the never A229 Pro cameras since your post I quoted was tested with the older camera as @Nigel pointed out? Also, what is your stans on HDR or not to HDR during the day? That is if you have any experience with the A229 Pro since different brands have different versions of HDR and might not compare.
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I don't own a A229 Pro (yet) so it is hard for me to provide a knowledgeable opinion. Also, I live in the U.S.A which like most countries in the western hemisphere uses smaller license plates than in Europe and the UK and so US plates are much more challenging to capture. Interestingly, I live in a location that is adjacent to two other states and we also have many tourists and visitors from other states so it is common to see many different license plates of different colors with different lettering, numbers and graphics. Some can be easier to capture than others, both day and night. My home state of Vermont probably has the most legible with large white reflective lettering on a plain dark green background.

These days I've been using a A119 Mini 2 camera up front and so I use the HDR timer at night but it doesn't seem to do much for me. Unfortunately, despite all the hype I have been rather disappointed in the performance of the MIni 2, especially in regard to motion blur in any conditions and am still trying to understand why that is. This is my second unit as the first was replaced due to an out-of-focus issue and the new one is not all that much better really, plus the camera does other weird unexpected things like triggering the G-sensor when making a slow turn in a parking lot even at the lowest setting.

Anyway, this is not the place to go into this in detail but I'm trying to say that I'm probably not the best person to ask about HDR and license plate capture at the moment but I do use a camera with a Starvis 2 sensor.

As far as CPLs are concerned and the comments we often see about how they don't affect camera exposure, as I've said on this forum before, you just can't argue with the laws of physics.

In fact, I've been running my A119 Mini 2 without the CPL lately and instead using a dash mat only to see if I can't improve the poor motion blur results I'm experiencing with the camera.
 
Dashmellow said:
I don't own a A229 Pro (yet) so it is hard for me to provide a knowledgeable opinion. Also, I live in the U.S.A which like most countries in the western hemisphere uses smaller license plates than in Europe and the UK and so US plates are much more challenging to capture. Interestingly, I live in a location that is adjacent to two other states and we also have many tourists and visitors from other states so it is common to see many different license plates of different colors with different lettering, numbers and graphics. Some can be easier to capture than others, both day and night. My home state of Vermont probably has the most legible with large white reflective lettering on a plain dark green background.

These days I've been using a A119 Mini 2 camera up front and so I use the HDR timer at night but it doesn't seem to do much for me. Unfortunately, despite all the hype I have been rather disappointed in the performance of the MIni 2, especially in regard to motion blur in any conditions and am still trying to understand why that is. This is my second unit as the first was replaced due to an out-of-focus issue and the new one is not all that much better really, plus the camera does other weird unexpected things like triggering the G-sensor when making a slow turn in a parking lot even at the lowest setting.

Anyway, this is not the place to go into this in detail but I'm trying to say that I'm probably not the best person to ask about HDR and license plate capture at the moment but I do use a camera with a Starvis 2 sensor.

As far as CPLs are concerned and the comments we often see about how they don't affect camera exposure, as I've said on this forum before, you just can't argue with the laws of physics.

In fact, I've been running my A119 Mini 2 without the CPL lately and instead using a dash mat only to see if I can't improve the poor motion blur results I'm experiencing with the camera.
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Thanks for your opinion.

I guess I'll run a few more tests to see the difference but it's getting a bit tedious now and I might lose interest soon as my honeymoon period with this new dashcam coming to an end :D
I just thought there would be someone on this forum that already done all these tests with their A229 Pro and has recommended settings, since this dashcam was released last year I believe?!?!
 
Paulbri said:
I just thought there would be someone on this forum that already done all these tests with their A229 Pro and has recommended settings, since this dashcam was released last year I believe?!?!
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No doubt there are probably many on the forum who have done all sorts of OCD testing and someone may offer up some useful advice but everyone's personal experience can differ when it comes to your particular vehicle, your usual driving circumstances and preferences so it is up to you to be the final arbiter of what works best for you. For example, I live in a rural, heavily forested area where I find myself often (but not always) driving under a canopy of trees and so even on a sunny day the shadowy conditions can create more motion blur than one might expect so it can be a judgement call about how to set the camera's exposure or whether or not to use a CPL and this changes at different times of year.
 
Okay a little video from today.
With CPL on the A810 and i also think it is a bit less light VS last video, so yes plates are suffering here.
You will also notice i pause 1-2 frames further out, CUZ letting them come closer and it is interly a blur.

 
no i did not think of removing it, i will try to see if i can do that on a later drive.
I have mainly used CPL filters in the past 10 years or so.
While a CPL do block some light, i am more inclined to think its a bit darker than in my last video, recorded 1 hour earlier in the day, though here i do think it is a case of thickness of the cloud cover, today was very humid and hot ( 25 deg C )

Also in the first video i linked to i am driving west, in this one i am driving east, it is recorded on the same road but there is a few KM in between the two spots.
 
I did some more testing and definitely in my case with this camera in this car in this country I'm going no CPL filter. Here are screengrabs from videos with and without CPL showing how it affects reflection compared to licence plate legibility and there is no contest for me. As I mention before I rather see licence plates compared to a bit less reflection.

1 - no CPL
2 - with CPL
3 - Licence plate no CPL
4 - Licence plate with CPL
 

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cea5t said:
You're right, I don't understand. Never mind, I'll just go back to sleep. LOL
Click to expand...
I made the same mistake about 4K resolution and @safedrivesolutions smacked me upside the head long distance-like and set me straight :)

This was the key per @Paulbri 's post:
  • Oh, and just to keep you on your toes, you might hear 4K resolution casually referred to as “2160p.”
 
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Hack_man said:
I made the same mistake about 4K resolution and @safedrivesolutions smacked me upside the head long distance-like and set me straight :)

This was the key per @Paulbri 's post:
  • Oh, and just to keep you on your toes, you might hear 4K resolution casually referred to as “2160p.”
Click to expand...
maybe it is time to make a video about the 2160p misunderstanding. I just had someone the other day on the phone telling me they lost resolution going to 2 and 3 channel mode. This is a common misunderstanding. Maybe the manufacturer should just have it say 4K + 1080p + 2K or whatever
 
safedrivesolutions said:
maybe it is time to make a video about the 2160p misunderstanding. I just had someone the other day on the phone telling me they lost resolution going to 2 and 3 channel mode. This is a common misunderstanding. Maybe the manufacturer should just have it say 4K + 1080p + 2K or whatever
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@viofo should make the menu even simpler "4K + 2K + 1K". Yes, in reality 1K is much closer to 2K horizontally than 2K is, but the numbers make sense in detail terms, 2K has twice the pixels of 1K (FHD), 4K has twice the pixels of 2K. 1080 is obviously 1K because it is 1000ish pixels, just that this one is measured vertically instead of horizontally for some reason.


Although a lot of people use "1080p", if you are buying a TV, it is "FHD", so is what most people know. Almost nobody knows what the 'P' means, and everything has been 'P' since the end of analogue video, so there is no need to include it, unless you are actually going to have an 'I' (interlaced) option!

With the menu saying "4K + 2K + 1K", there would be no confusion, the manual can give the exact resolutions, or people can check the file properties.

4K + 2K + 1K, 30fps, 16;9​
4K + 2K + 1K, 30fps, 21:9​
2K + 2K + 1K, 60fps, 16;9​
2K + 2K + 1K, 30fps, 16;9​
1K + 1K + 1K, 30fps, 16;9​
 
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