Polarizing filters do they help?

[Tajee]

Any feedback on polarizing filters and do they make a difference? Are they used only during daytime or can they be used for interior recording at night with a IR camera? I'm using the BlackVue DR650S -2CH-IR unit.

 

[jokiin]

what problem are you trying to overcome?

 

[Rajagra]

They improve the image a lot if the windscreen is reflecting a brightly lit car interior. It could be the difference between a number plate being readable or not.
But they will degrade the image if light is dim.
I can't think of any advantage in using a polarizing filter for interior recording (whether IR or not.) It would just make the sensor's work harder.

 

[iptelman]

I consider a CPL filter a requirement for daytime driving. (Pointed out the front window)

 

[Street Guardian USA]

Here are some examples of a CPL in action:

https://dashcamtalk.com/forum/threa...ns-filter-for-street-guardian-sg9665gc.14256/

 

[Kip]

It's worth pointing out that each camera is different and mounting locations can also affect how many reflections you get. My first camera did not have a CPL filter but it didn't suffer too badly. My current camera, however, does come with a CPL and it's just as well because without it, I was getting really bad reflections that were making day time footage pretty awful at times. It does impact on night time quality, however, this depends on the quality of the CPL. My JooVuu X CPL stays on all the time now as it doesn't take too much away from night footage. Some other CPLs can make night footage pretty bad, it just depends on the camera.

 

[iptelman]

As a general rule, the closer the lens is to the glass, the less of a problem you will have with interior reflections.
A CPL will always reduce the amount of light available so while some cameras will compensate at night, I'd still recommend it be removed.

 

[DT MI]

As a general rule, the closer the lens is to the glass, the less of a problem you will have with interior reflections.
....

Really depends on the specific vehicle so there is no 'general' rule. In fact, most anecdotal evidence on this forum tends to demonstrate just the opposite. See this post/thread for examples: https://dashcamtalk.com/forum/threa...n-the-right-cameras.20413/page-10#post-277887

 

[Kip]

Really depends on the specific vehicle so there is no 'general' rule. In fact, most anecdotal evidence on this forum tends to demonstrate just the opposite.

My experience exactly. Old camera was further away from the glass than the current one is. They are mounted differently though. My JooVuu X is mounted right below the rear view mirror as due to its small size I can get a central view point here. My old camera was mounted behind the rear view mirror on the passenger side.

 

[Rajagra]

The closer you get to the glass, the more the reflection 'zooms in' to a specific area inside the car.
That might be a sweet spot that isn't reflecting much ... or a sour spot that means the whole image contains a bright reflection.
If that brightness contains little texture, you may not even recognize it as reflection - but the even spread of added whiteness can destroy contrast in darker areas of the true image.