Best Dash-cam Video quality?

[superclarkey]

Before you jump on the latest device that's only just been announced, you might want to wait for some video samples to see if it really is an improvement. The 1440p IMX335 A113V3 should have been an improvement over your old 1080p IMX291 470W+ but for whatever reason you felt the video quality was around the same. Quality is subjective though. Viofo products generally tend towards relatively high contrast and sharpening for the purpose of capturing dashcam evidence rather than looking good.

Also consider the physical format of the A139 series. It is a wide wedge style, no screen, with the lens offset to the right. Now, that's ideal for me but it will not suit everyone. It seems likely that there will be an A229 Pro within a few months, which will have 4K Starvis2 and be a similar shape to your A119V3, including a screen.

Makes allot of sense, thanks

 

[Nigel]

Are you actually being serious? The aperture of the lens has no effect on motion blur.

how can I take anything you say from this moment on seriously lol

That was the wrong answer!
You might want to reconsider...

Why is a lens with a big aperture such as F/1.6 like your dashcam lens known as a "fast lens", while a lens with a smaller aperture such as F/4 on your DSLR is called a "slow lens"? The fast and slow refer to motion blur.

 

[superclarkey]

Dunning-Kruger effect in action.
Aperture will never have any effect on motion blur, from now until the end of time..

One thing it does effect is amount of light that that passes to the sensor, and to keep a constant EV (exposure) you must change one of the other variables which one does change motion blur.

Saying aperture causes motion blur is like saying if I press the throttle in my car the physical act of pressing the throttle down is what pushes the car forwards, when in reality the change to the throttle position causes a change to the rpm/load of the engine which actually drives the engine forward.

So no the throttle doesn’t make your car go any faster, your engine does.

The only thing that changes motion blur is shutter speed, fact, not up for debate.

The other two things you can change is ISO and/or aperture, neither have any effect on motion blur, they change how much light is able to pass to the sensor, and how much you boost the signal from the sensor.

if you wish to keep the same exposure then if you from say f/1.4 to f/4 that is 2 stops different, or we can say the f1.4 let’s in 4 times the amount of light at f/4

So your going to have an image that is 4 times darker than at f.4 original, so you can either boost the signal by adjust the ISO 2 stops, say from ISO400 to ISO1600, or if the shutter speed is at 1/60th going 2 stops would be 1/15th for the same exposure. Both ways compensates for the darker image.

So if your statement was true that aperture that controls the amount of motion blur then it would have this results in both ways of correcting the exposure, whether it be from ISO adjustment OR shutter speed adjustment.

The fact is that ISO will not change the imaged blur level captured, as it is only boosting the signal.

So in conclusion, aperture has no effect on motion blur, but can cause settings to change (I.e shutter speed) in compensation to get the same EV which will effect the change of motion blur, but if we had variable ISO it wouldn’t.
As I clearly said a DSLR can break the 180rule shutter rule, typically when the fps is say 30, you would expose for 1/60th of a second, so this will give you smooth looking footage which is nice on the eyes, but if you go for a 90 degree shutter angle where the frame is now open for 1/125th of a second your going to have more unnatural looking movement, but each frame within that 30fps will be less blurry at the expense of loosing a stop of light, which you would need to compensate for in one stop of ISO. You can go further to 45degree etc.

It’s a balance between being a series of photos that do not blend for when watching back a whole clip vs freeze framing to say grab a detail non blurred shot of a number plate.

If you have a fixed ISO film (not digital) then of course changing the aperture, then your only option is to adjust shutter speed to compensate, so a wide open lens (fast lens) would allow a faster shutter speed for the same exposure of a shut down lens which would require a slower shutter speed to get the same exposure.

 

[Nigel]

or we can say the f1.4 let’s in 4 times the amount of light at f/4

Actually, that is 8 times the amount of light, which to keep correct exposure will require 1/8th the shutter speed, resulting in 1/8th the motion blur.

So based only on the aperture difference, and correcting the exposure using shutter speed, at the moment it looks like your DSLR is going to have nearly 8 times more motion blur than your A119 V3 dashcam... how much of that can you recover using ISO?

As I clearly said a DSLR can break the 180rule shutter rule,

What makes you think that a dashcam can't? That rule is of no relevance to the task of recording dashcam evidence.

 

[Nigel]

The 1440p IMX335 A113V3 should have been an improvement over your old 1080p IMX291 470W+ but for whatever reason you felt the video quality was around the same.

The IMX291 is a good sensor, the IMX335 has a small advantage due to twice the resolution, some of which is lost due to worse sensitivity and dynamic range, they are both Starvis-1 sensors, more or less the same generation of technology. For recording large UK number plates, the A119 V3 should be a small improvement, not a major leap forward, and maybe not in heavy rain. For smaller plates it is a more significant improvement. The HDR available on the A119 V3 may also help.

If you want next generation performance then you need to look to Starvis-2 and the Viofo A139 Pro.