1920x800/540 video mode?

[kevindd992002]

The CPL/Tinted windscreen/Rainbow effect I'm talking about is a phenomenon in physics called "birefringence".

See these two posts for an example and a more thorough explanation.

https://dashcamtalk.com/forum/threads/viofo-a129-modified-firmware-mods-archive.35826/post-453920

https://dashcamtalk.com/forum/threads/viofo-a129-modified-firmware-mods-archive.35826/post-453932

Is this CPL rainbow effect present even if the tint is of ceramic type? Or does the tint type even matter?

Is there any other way to know if the Viofo CPL will produce this effect in my case without actually buying the filter first?

Sent from my SM-G950F using Tapatalk

 

[Nigel]

Why on earth would anyone want to use 4:3 aspect ratio...

4:3 aspect ratio video seems very popular for action cameras used on bikes. Seems to match the aspect ratio of the vehicle better, just as 32:9 matches my low height car better.

 

[Dashmellow]

Is this CPL rainbow effect present even if the tint is of ceramic type? Or does the tint type even matter?

Is there any other way to know if the Viofo CPL will produce this effect in my case without actually buying the filter first?

Sent from my SM-G950F using Tapatalk

I'm not certain about how different tints work with this. One way to test it without purchasing a CPL filter is to look through your windscreen while wearing polarized sunglasses. (This is referenced in one of the links I posted above. Here's the link directly. It will explain the topic further, especially about polarized sunglasses - https://www.revantoptics.com/blog/why-youre-seeing-rainbows-in-car-windows/)

 

[Dashmellow]

4:3 aspect ratio video seems very popular for action cameras used on bikes. Seems to match the aspect ratio of the vehicle better, just as 32:9 matches my low height car better.

I'll stick with 16:9 thanks. I'm not driving a bike. I take your point but I disagree that 32:9 matches a low height car all that better as you are still eliminating important data from your capture, but again, as always, do what pleases you.

Granted, this image is a poor example and indeed it is from a higher vantage point but it is meant to be illustrative. Note that with the vehicles on either side of my vehicle the license plates are outside the FOV. They are quite low to the ground actually. This could easily happen with a low chassis vehicle especially if another low chassis vehicle is coming at you. Personally, I see no reason to risk missing something important if it is entirely unnecessary to do so.

 

[nutsey]

Note that with the vehicles on either side of my vehicle the license plates are outside the FOV.

Please don't forget about massive barrel distortion of these lenses. So, if you raise your cam to the position where the green rectangle is in the center those license plates also should move higher.

 

[Dashmellow]

Please don't forget about massive barrel distortion of these lenses. So, if you raise your cam to the position where the green rectangle is in the center those license plates also should move higher.

Yes, I've thought about that and you make a good point, but of course, with such a narrow vertical FOV you risk losing the capture of certain traffic signals and signage (and giant meteors falling from the sky ). My view is that as appealing as these wide captures may be there will always be a compromise of some kind. I do like the idea of using two cameras with two fields of view though.

 

[Dashmellow]

Please don't forget about massive barrel distortion of these lenses. So, if you raise your cam to the position where the green rectangle is in the center those license plates also should move higher.

BTW, is the 1920 x 540 video you posted a setting in your camera or is it a post capture video edit? That would make a big difference with this approach.

 

[nutsey]

BTW, is the 1920 x 540 video you posted a setting in your camera or is it a post capture video edit? That would make a big difference with this approach.

Intact file with no editing directly from my camera.

 

[Dashmellow]

Intact file with no editing directly from my camera.

That's interesting. Which camera is it?

 

[nutsey]

That's interesting. Which camera is it?

Pre-production sample based on NT96658+IMX323.

 

[Dashmellow]

Pre-production sample based on NT96658+IMX323.

Interesting. My only personal experience with a "cinema mode" type format was when I was testing a pre-production mini 0806 that had a 21:9 option of 2560x1080 30fps . I really like it at first but after awhile I went back to the more tradition aspect ratio. Still, that was somewhat different than we've been discussing here.

 

[nutsey]

Interesting. My only personal experience with a "cinema mode" type format was when I was testing a pre-production mini 0806 that had a 21:9 option of 2560x1080 30fps . I really like it at first but after awhile I went back to the more tradition aspect ratio. Still, that was somewhat different than we've been discussing here.

Got mine not for testing but for tweaking as an independent action/dash cam enthusiast

 

[Nigel]

(and giant meteors falling from the sky ).

I've never missed filming one yet due to using 32:9! Of course there is a chance, but do I want to loose 50% of the detail in all my videos just so that I would catch the meteor if it ever did fly over? I think I would be better off installing a special meteor cam facing vertically upwards to catch it as it goes overhead, not many of them fly low enough to enter even 16:9.

BTW, is the 1920 x 540 video you posted a setting in your camera or is it a post capture video edit? That would make a big difference with this approach.

Of course if you do it in the edit then you can still go back and see that meteor in the original footage, but then you don't benefit from the memory saving/quality improvement - Another compromise.

 

[Dashmellow]

I've never missed filming one yet due to using 32:9! Of course there is a chance, but do I want to loose 50% of the detail in all my videos just so that I would catch the meteor if it ever did fly over? I think I would be better off installing a special meteor cam facing vertically upwards to catch it as it goes overhead, not many of them fly low enough to enter even 16:9.


Of course if you do it in the edit then you can still go back and see that meteor in the original footage, but then you don't benefit from the memory saving/quality improvement - Another compromise.

Seriously, you're gonna' take a humorous reference to the Chelyabinsk meteor event captured on so many Russian dash cams and start arguing about the best methods for capturing dash cam footage of meteors and making ridiculous boasts about having "never missed filming one yet due to using 32:9!" Get a life, Nigel.

 

[Nigel]

Seriously, you're gonna' take a humorous reference to the Chelyabinsk meteor event captured on so many Russian dash cams and start arguing about the best methods for capturing dash cam footage of meteors and making ridiculous boasts about having "never missed filming one yet due to using 32:9!" Get a life, Nigel.

The only time I've seen a big meteor, I didn't have any sort of video camera with me, but if I had had a 32:9 camera it would have recorded it since the meteor went right down to the horizon before exploding, and the microphone would have recorded the bang too.

 

[TonyM]

Personally, I see no reason to risk missing something important if it is entirely unnecessary to do so.

 

[jokiin]

Pre-production sample based on NT96658+IMX323.

the 1920 x 540 is just a crop, could be done on any camera, not sure what the benefit would be

we were offered a solution previously that did similar but it was 1920 x 540 front and rear and the output was muxed into a 1920 x 1080 file so you got front and rear view in the one file at the same time, it was effective but you gave too much away with only 540 lines of vertical resolution captured

 

[TonyM]

the 1920 x 540 is just a crop, could be done on any camera, not sure what the benefit would be

we were offered a solution previously that did similar but it was 1920 x 540 front and rear and the output was muxed into a 1920 x 1080 file so you got front and rear view in the one file at the same time, it was effective but you gave too much away with only 540 lines of vertical resolution captured

Some people like to present their dual channel video in 2x 1920x540, so that off-the-shelf solution might please them. I think it's an interesting way to record using only one file rather than two, which as Nigel points out then gives you longer recording time on a card, but at the end of the day I'd rather have 16:9 for each view to make sure I don't miss something important above or below.

 

[jokiin]

I think as an edit it's a nice way to present it, but I'd still want the detail from the full frame videos which could easily be missed when the crop is hard coded

 

[Dashmellow]

The only time I've seen a big meteor, I didn't have any sort of video camera with me, but if I had had a 32:9 camera it would have recorded it since the meteor went right down to the horizon before exploding, and the microphone would have recorded the bang too.

Of course, you'd need to be pointing the camera in the exact right direction at the exact right moment and that is highly unlikely. I can tell you that from experience actually as I've witnessed quite a few meteor showers and random fireballs drop out of the sky. Catching them on camera is a challenging and tricky thing to do. The best ones have a funny habit of occurring just out of the frame or not fully in the frame when you have a lot of sky to cover. I'm fortunate to live on a property where I have a commanding 100 mile mountain view and a vast expanse of sky out the picture window of my living room and off my deck. Over the many years I've lived in this location I've seen quite a few. Many are typical shooting stars and meteors and can even be quite bright and long lived but occasionally a few have been astonishingly large and this happens far more often than many people might think. Typically, we'll be relaxing on the deck on a summer night and all of a sudden a huge fireball shoots across or drops straight down vertically from the sky. And yes, they can make quite a loud bang! One was quite startling as it not only was the biggest one I've ever seen but was visible for a long time and made a loud report as it left a trail of smoke that lingered quite some time in the sky. It started as a large yellow flash and a loud bang that turned into streak across the sky and ended in a bright green fireball. Occasionally, we gather for early morning "Perseid Parties" during the seasonal meteor shower and several meteors will yield loud bangs on a good year.