SGGCCPL Circular Polarizing ( CPL ) Lens Filter for Street Guardian SG9665GC

Put a white piece of paper on the dashboard. Manually hold the CPL out in front of the lens unattached and slowly spin it 360 degrees. See if the white paper disappears at different angles than the factory set angle. It's possible your glass was not inserted correctly. I'm viewing on my iPhone currently so didn't get a good look but try that. We'll sort it out either way.
 
budster said:
I'm finding that the CPL is not working as well as I thought it should in cutting down windshield reflections. Even on overcast or rainy days, I'm still seeing tons of reflections in the windshield. Below are some screenshots under different conditions. Are my expectations not correct for what the CPL should do or might I have a defective CPL?
Click to expand...

it must be out of alignment
 
budster said:
I'm finding that the CPL is not working as well as I thought it should in cutting down windshield reflections. Even on overcast or rainy days, I'm still seeing tons of reflections in the windshield. Below are some screenshots under different conditions. Are my expectations not correct for what the CPL should do or might I have a defective CPL?


View attachment 18557 View attachment 18558 View attachment 18559 View attachment 18560 View attachment 18561
Click to expand...

Best way to test is to park your car the way you see a lot of dashboard reflection and perform similar tests like on my videos below then later compare with and without CPL scenes.




 
hold the filter up in front of an LCD monitor, look through from the camera side and rotate it, at what position does it go black?
 
jokiin said:
hold the filter up in front of an LCD monitor, look through from the camera side and rotate it, at what position does it go black?
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When I turn the CPL counter clockwise about 45 degrees, the LCD monitor turns black.
 
Pier28 said:
Put a white piece of paper on the dashboard. Manually hold the CPL out in front of the lens unattached and slowly spin it 360 degrees. See if the white paper disappears at different angles than the factory set angle. It's possible your glass was not inserted correctly. I'm viewing on my iPhone currently so didn't get a good look but try that. We'll sort it out either way.
Click to expand...

I did this test in a garage with an overhead fluorescent tube lighting. I never saw the paper completely disappear, but the paper reflection seemed to be faintest when I turned the CPL 90 degrees.
 
This means your lens was seated incorrectly. We can either have you try and eject, rotate, re-insert the glass yourself or I can send you a new one with a return label. USPS first class is only $2.50 so it's not a problem.
 
Pier28 said:
This means your lens was seated incorrectly. We can either have you try and eject, rotate, re-insert the glass yourself or I can send you a new one with a return label. USPS first class is only $2.50 so it's not a problem.
Click to expand...

Ok, looks like it's very easy to rotate the lens without removing it from its holder since the lens sticks out a little bit on the top and bottom. Using one finger on the top and another on the bottom, I can turn it easily. Does this sound right to be able to do this?

If I hold up the CPL to a LCD monitor (that's turned on and is displaying something on the screen) and look thru the CPL, should it look black for the orientation to be right? I've gone ahead and done this, so if that's all then, I think I'm good now.
 
Ok great. Turn it so the live view of the white paper on the dash test is minimized as possible. You're all set after that.
 
budster said:
When I turn the CPL counter clockwise about 45 degrees, the LCD monitor turns black.
Click to expand...

then it was out by close to 45 degrees, when you turn it 90 degrees it should go black, sounds like it had shifted, going forward they're going to be glued in place once set
 
So if I do the LCD monitor test and look thru the CPL, should it look black? That's a very easy test for me to do.

The white paper test on the dash is a bit harder for me. I can't easily rotate the CPL while the dashcam is mounted and it's not so straightforward for me to tell when the white paper reflection is minimized the most. Seems to depend where the white paper is located.
 
Do what ever is easiest but I'm not exactly sure what you mean by "should it look black". Help us understand what 'it' is and how you're testing exactly step by step.
 
Oh I see you simply look through it as you aim it at a computer LCD monitor screen and it will look black. (Edit: when vertical, see next post) That sounds easy rough.
 
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I need to understand the LCD monitor test that @jokiin mentioned a little better. So when I hold up the CPL to the monitor in the horizontal position (like how it would be on the dashcam), when looking thru the CPL, should the LCD monitor screen look black? Or should it look black when I turn the whole CPL 90 degrees and it's oriented vertically? Or should it look black at a different angle? I'm a little confused because with my polarized sunglasses, I can view what's on the LCD monitor when wearing them normally, but when I turned my head 45 degrees clockwise, then the LCD monitor screen turns black.

Here's some pictures of me holding the CPL up to a LCD monitor at different angles where I've rotated the lens such that looking thru it, the LCD screen shows as black. Which one is correct?

(horizontal)
IMG_0295.JPG


(vertical)
IMG_0296.JPG

(turned 45 degrees clockwise)
IMG_0297.JPG
 
jokiin said:
when vertical it should be black, rotate the lens until it's black when held in that position
Click to expand...

Thanks, I've gone ahead and done this. Hopefully, will see less reflections when out on the road later.

Seeing now how easy it is to rotate the lens within the holder, I'm not sure now if I accidentally did this myself before when installing the CPL on the dashcam before (did this many times due to the loose fit issue that I was playing around with) or when trying to clean the lens due to what turned out to be a couple imperfections in it. I guess gluing the lens in position would make user error impossible, but less correctable in case the lens was ever mis-asligned out of the factory.
 
mine where im not over excited about but it still works ok.
if I turn 45 degrees clock wise and 225 degrees clockwise it goes all black in both those positions.
 
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