30fps v 60fps

Kremmen

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Dash Cam
2 x Viofo A119 V3
I'm going to have to eat some humble pie.

I've been running at 2560x1440 60fps for ages and viewing the footage it looks smoother, however I've just been going through some footage to grab a screenshot of a speed camera.

All the 60fps freeze frames have motion blur but going back to when I ran 30fps which would have been pre v2 firmware all the freeze frames are a lot sharper with no blur.

= back to 30fps and see what happens next week.
 
Having studied various frames it seems to me that 60fps may be a software based implementation much like the HDR/WDR posted here that implements extra frames ...... and often fails.

My freeze frames were on a motorway at 60mph and the nearside street furniture is definitely sharper at 30fps than 60fps in screenshots.

I'm not planning doing that motorway till next weekend so I'll find out then.
 
OK.

I was basing my guess on the HDR type posts where the software is reported to implement an additional frame and causes the motion blur. I do have HDR turned off.

I'l be interested to see the difference in about 10 days.

Here is my current :

60fps firmware 2.00:

IupqHtf.jpg


30fps firmware 1.03:

anfEmuF.jpg


Quite a difference

However, here is a 30fps screenshot under firmware 2.00 but this was at dawn so poor light so presumably enhanced ?

gORcCcd.jpg


Confirmed, found a similar low light file under 1.03 and has motion blur.

Testing to commence soon .........................
 
Last edited:
That last shot was 30fps but poor light. I did set it to 30 for 1 week back in Feb and I found it.

I'll be along that same section a week on Friday, good light hopefully.
 
That last shot was 30fps but poor light. I did set it to 30 for 1 week back in Feb and I found it.
yes I know, what I said was if it was running at 60fps that same shot would be expected to look worse in those conditions
 
Got ya :)
 
@Kremmen, keep in mind that there are two different things going on simultaneously that will determine motion blur - frame rate plus shutter speed. In a traditional film camera it would be mechanical but in a digital dash cam it is done electronically.

Frame rate - Frame rate is how many individual frames you are capturing per second.

Shutter speed - Shutter speed is the duration of time each individual recorded frame is exposed to light. Just like in photography, the higher the shutter speed for video, the more you’re going to freeze any moving objects in each of your frames. Conversely, the lower the shutter speed, the more blur will occur for those same moving objects.


So, you could have the camera set to 60 fps and it might be shooting at a 1000th of a second in very bright light.
You could have the camera set to 30 fps and it might also be shooting at a 1000th of a second in very bright light
.

Under overcast low light conditions the camera would be shooting at a much slower shutter speed than in bright light but it would still be shooting at 60fps or 30fps.

See THIS LINK for a helpful interactive demonstration.

Keep in mind that dash cams and action cams can sometimes also change frame rates dynamically as well but that is a different subject than the basic concept I am trying to explain here,


 
That last shot was 30fps but poor light. I did set it to 30 for 1 week back in Feb and I found it.

I'll be along that same section a week on Friday, good light hopefully.
I’m glad you raised this question as I have been very disappointed in any freeze frames I’ve tried and this discussion has thrown some light on it.
On an old Ambarella processor based dashcam (which was brandname less) unit the stills where just that, stills, no blur.
The blur while filming and pulling a freeze frame has been a disappointment with Viofo dashcams. However the playing video is fine, it’s only when I want to zoom in to an image that the frame rate/shutter become really noticeable.
Would be nice to know if it’s fixable.
 
I've got saved footage going back to when I got the V3 so I can compare various conditions through various firmware.

It only came to light because there is a strange new, what we think is a speed camera, on the M4 but is nothing like anyone has seen before. Not Specs and not Hadecs. It's front facing and has flashed me twice even though I was under the limit.

I didn't notice it flashing when I was driving so I'm wondering if it one of those strange effects you get triggered by the dashcam LED that I have activated.

The freeze frame isn't as sharp as I'd expected so time to investigate:

vBAK6rf.jpg
 
I didn't notice it flashing when I was driving so I'm wondering
Maybe an infrared flash, could be an average speed camera, but if it is not labelled with speed camera warning signs then it is probably just monitoring speeds. Maybe they are recording speeds to make a case for installing a real speed camera.
 
This is the M4 smart motorway roadworks between J3 and J12. There are currently 50mph Specs cameras and some new Hadecs3 cameras in the 60mph zone, where this one is, that, as you say, are being tested with appropriate signage.

This Truvelo style front facing seems an unusual one, not seen before but it's on a yellow Jenoptic style pole so we are watching at PocketGPSWorld.
 
I didn't notice it flashing when I was driving so I'm wondering if it one of those strange effects you get triggered by the dashcam LED that I have activated.

Some speed cameras are now using LIDAR for data capture, so it's possible your dash cam picked up a laser pulse.
 
Front facing and a flash - if I'd have known I'd have combed my hair :D
 
I asked Viofo what they recommend. They said "I would recommend 2560x1440P @30fps with HDR on. Because most people set to this resolution. And HDR can help improve the image at night."
 
I've got two A119 v3s, their setups are identical:

Resolution: 2560x1440P, 30FPS
Bitrate: High
Loop Recording: 1 minute
Video Format: MP4
EV Exposure: +0.0
WDR: On

However, both units are still on v1.03 firmware

I'm very happy with the day, dusk, and night footage (video and freeze frame)

I should have a look at the notes for the later firmware.

Regards,
 
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