Night time quality with CPL filter on

[mihai21roo]

Hello,

I just installed the CPL filter (I did remove the protective films from both sides and also placed it on the correct side). Attached you can see a few images from the night quality. This is looking absolutely terrible and grainy, what did I spend extra money on?

I have also attached a screenshot in similar conditions with CPL off.

 

[gse]

To reduce digital noise, you need to shift the exposure to a minus value.
For night video you need to enable HDR.
For a better analysis, post a one-minute original video; the video must be uploaded to a file hosting service (Google Disk, DropBox, etc.) and the link to the video must be attached in the message.

 

[Dashmellow]

Viofo's CPL filters are made with polarizing film sandwiched between two pieces of optical glass. I recall some of the earlier versions of the filter (which were offered by both Street Guardian and Viofo) had an issue where the glass layers began to separate due to a manufacturing defect. (I received one of those from SG.) It is "possible' such a problem could be manifesting here.

Examine the filter closely under bright light and see if there is anything noticeably wrong with the filter such as lines inside the glass or moire patterns and also try the camera with and without the filter.

 

[mihai21roo]

To reduce digital noise, you need to shift the exposure to a minus value.
For night video you need to enable HDR.
For a better analysis, post a one-minute original video; the video must be uploaded to a file hosting service (Google Disk, DropBox, etc.) and the link to the video must be attached in the message.

I'll try HDR on and minus value exposure at night time then. HDR on made my image look worse without the CPL filter so I'm not expecting much though.

I also prefer to use 60 fps during the day, but if I set the HDR on Auto, it will stay at 30 fps even after the HDR automatically turns off. Very annoying.

Dropbox link with the video - the quality doesn't seem to be as good as on my PC though.

Viofo's CPL filters are made with polarizing film sandwiched between two pieces of optical glass. I recall some of the earlier versions of the filter (which were offered by both Street Guardian and Viofo) had an issue where the glass layers began to separate due to a manufacturing defect. (I received one of those from SG.) It is "possible' such a problem could be manifesting here.

Examine the filter closely under bright light and see if there is anything noticeably wrong with the filter such as lines inside the glass or moire patterns and also try the camera with and without the filter.

Thanks for the tip. I just ordered this from Viofo's website a few weeks ago. I hope they're not still selling those batches with manufacturing defects, but I will still check the filter.

 

[Dashmellow]

The defective filters were mostly from a long time ago, but it is possible this could still happen on rare occasions. It's worth checking.

 

[speedingcheetah]

I also prefer to use 60 fps during the day, but if I set the HDR on Auto, it will stay at 30 fps even after the HDR automatically turns off. Very annoying.

I have 2x A119 Mini 2's and both are set to use 2K/60fps day, and night 2K 30fps. U set the HDR Timer function, on time, off time and the camera changes back to the 60fps mode during the day (HDR off).
EDIT: Not sure of the A119 V3 has this function.

I have had CPL on my front cam, since 2016 (a A119 V1). It never affected night image. Still use CPL at all times. It is not practical to remove it/ re install it so often.
Seen many testers vids on the various cams VIOFO makes, CPL on and off for night footage, imo, it only but helps reduce glare and reflections, even at night.
(I do not have a CPL on my rear cam, as my rear window has 50% Tint on it, that is already polarized.)

The footage you show is not at night, but dusk or still partial light out. Both non-HDR, and HDR it gonna look grainy and not ideal for that in-between conditions.
I at first, thought HDR was crap, compared to the WDR on my old cam, but was told on here, that HDR is best after dark, not when it is still light out.
See my post here:

Viofo A119 M2 HDR poor vs old A119 v1 WDR (low light/day)

Thought the new A119 Mini2, be the latest and greatest fancy sensor was superior with HDR and all that..... So why does it look darker, much more Nosie and just crappy compared to my old and very well used A119 V1 that has "WDR"? I also notice the A119M2 switches between this grainy noisey...

dashcamtalk.com

When enabled at the proper time, HDR, at least on the VIOFO A119 Mini 2, is TOP NOTCH!
See my re-test, same location, when it was fully dark out.

Viofo A119 M2 HDR poor vs old A119 v1 WDR (low light/day)

Now that I have two A119 Mini 2 dash cameras with the updated lens, I'll finally be able to complete my A119 Mini 2 review. I will gather "HDR On" vs "HDR Off" day/night footage since I have two of them that I can run at the same time. I just need to get through my testing of the A229 Pro /...

dashcamtalk.com

You may also want to check the glass on the CPL, clean it (and you camera lens) with some eyeglasses lens cleaner and micro fiber cloth. Often the plastic will leave residue on it.

 

[mihai21roo]

What camera? I have 2x A119 Mini 2's and both are set to use 2K/60fps day, and night 2K 30fps. U set the HDR Timer function, on time, off time and the camera changes back to the 60fps mode during the day (HDR off).

I have had CPL on my front cam, since 2016 (a A119 V1). It never affected night image. Still use CPL at all times. It is not practical to remove it/ re install it so often.
Seen many testers vids on the various cams VIOFO makes, CPL on and off for night footage, imo, it only but helps reduce glare and reflections, even at night.
(I do not have a CPL on my rear cam, as my rear window has 50% Tint on it, that is already polarized.)

The footage you show is not at night, but dusk or still partial light out. Both non-HDR, and HDR it gonna look grainy and not ideal for that in-between conditions.
I at first, thought HDR was crap, compared to the WDR on my old cam, but was told on here, that HDR is best after dark, not when it is still light out.
See my post here:

Viofo A119 M2 HDR poor vs old A119 v1 WDR (low light/day)

Thought the new A119 Mini2, be the latest and greatest fancy sensor was superior with HDR and all that..... So why does it look darker, much more Nosie and just crappy compared to my old and very well used A119 V1 that has "WDR"? I also notice the A119M2 switches between this grainy noisey...

dashcamtalk.com

When enabled at the proper time, HDR, at least on the VIOFO A119 Mini 2, is TOP NOTCH!

You may also want to check the glass on the CPL, clean it (and you camera lens) with some eyeglasses lens cleaner and micro fiber cloth. Often the plastic will leave residue on it.

Viofo A119 V3 does that! I use 1440p@60 during the day, and as soon as HDR turns on automatically via the HDR Timer function, it changes to 30 fps. The next morning, I'll have HDR off but it won't revert back to 60 fps unless I manually change it from the settings. Maybe @viofo can confirm if they're aware of this issue?

I'll try cleaning the glass and the camera lens. I'll also try having a passenger remove the CPL filter during the drive so I can compare the footage at the exact same time, and then I'll post the results here. I really hope the residue from the plastic or even my fingerprints are the culprit. Otherwise... I'll just have to keep the filter off as I was happy with the video quality before installing it.

 

[ogzogz]

@mihai21roo

It looks like your headlight adjustment is low and centered.
Also, it seems to be less violent. may require an adjustment.

Light is important for HDR.

Does your vehicle have height adjustment according to load weight?
If there is, turn it to "0" position when there is no load.

If you adjust the headlights and use the required height adjustment, your problem will disappear.
(I am waiting for a video or image after applying my recommendations)

 

[Karagandinez]

Dropbox link with the video

You were asked to turn on HDR and upload the video to a file hosting service.
You posted a video at 60fps, but with these settings, HDR cannot be enabled.

Format : MPEG-4
Format profile : Base Media
Codec ID : isom (isom/iso2/avc1/mp41)
File size : 713 MiB
Duration : 3 min 0 s
Overall bit rate mode : Constant
Overall bit rate : 33.2 Mb/s
Frame rate : 60.000 FPS
Recorded date : 0
Writing application : Lavf58.44.100

 

[Kremmen]

Thanks for spotting 60fps, that needs turning off ..... then go again

 

[mihai21roo]

Sorry, I think I converted it to 60 fps with Handbrake since I had to remove the audio.

I have uploaded two new videos and they are no longer edited with any software:
HDR ON (30 fps): https://www.dropbox.com/scl/fi/cyct..._ON3.MP4?rlkey=vvynfay62mpik3zxwb5083k1t&dl=0
HDR OFF (60 fps - this is how I usually record at both day/night): https://www.dropbox.com/scl/fi/526c...FF_2.MP4?rlkey=jec9y1w2s1nwiythghwqw1y32&dl=0

I'll try to record without the CPL filter as well, I unfortunately forgot to remove it today.

 

[Karagandinez]

HDR ON (30 fps): https://www.dropbox.com/scl/fi/cyct..._ON3.MP4?rlkey=vvynfay62mpik3zxwb5083k1t&dl=0
HDR OFF (60 fps - this is how I usually record at both day/night): https://www.dropbox.com/scl/fi/526c...FF_2.MP4?rlkey=jec9y1w2s1nwiythghwqw1y32&dl=0

Are you sure you didn't mix anything up?
"HDR OFF (60 fps - this is how I usually record at both day/night):" = actually here 30 fps and more like shooting with HDR enabled.
Screenshot below. With HDR turned off, the numbers will not be visible.

 

[mihai21roo]

Sorry, not sure how I mixed those up. Seems like both are with HDR on.

This is HDR OFF 60 fps: https://www.dropbox.com/scl/fi/i9w1...FF_1.MP4?rlkey=vvt2hrt6s8f2rliarfcg20rwp&dl=0. The recording looks fine in those lightning condition, but when it's complete dark I can see a lot of digital noise with CPL on (as well as very bad quality).