CPL filter

[Liber8]

Does it matter which one I buy? Looking at Amazon theres a Viofo one for 19 bucks and a Spytec one for 13. I feel like being cheap here.

 

[DT MI]

You pay your money and you take your chances. Any specific reason you're 'cheaping out' for $6 on a $100 dash cam?

Spy Tec is a reputable company based on my experience and have a presence here ( @spytec ), as is OCD Tronic ( @OCD Tronic ), but I can't say for sure if the CPL they are selling is the VIOFO version or something they have sourced themselves from another manufacturer.

 

[OCD Tronic]

If you want one that's guaranteed calibrated correctly, with the good CPL glass, go with our listing.

 

[Deleted member 46308]

If you want one that's guaranteed calibrated correctly, with the good CPL glass, go with our listing.

This way you will definitely get what you are expecting, and from an honest and reputable seller.

 

[Ryne]

How do you know if it calibrated correctly?

 

[OCD Tronic]

How do you know if it calibrated correctly?

https://dashcamtalk.com/forum/threads/cpl-status.20524/page-23#post-305351
(most non-3D TV's work, but many computer monitors won't work since they are 45 degrees)

 

[Ryne]

Nice, thanks for that.

So mine's is installed incorrectly since it's clear when it's rotated 90 degrees and dark when it's horizontal (basically the colour of the lens is the opposite from the above picture)

Thanks, that is appreciated.

 

[OCD Tronic]

Nice, thanks for that.

So mine's is installed incorrectly since it's clear when it's rotated 90 degrees and dark when it's horizontal (basically the colour of the lens is the opposite from the above picture)

Thanks, that is appreciated.

Seems so, Quite possibly yes.

Put a piece of white paper on your dashboard and see if the white square reflection is minimized or there is no change in the video.

 

[jokiin]

Nice, thanks for that.

So mine's is installed incorrectly since it's clear when it's rotated 90 degrees and dark when it's horizontal (basically the colour of the lens is the opposite from the above picture)

Thanks, that is appreciated.

that depends which way the monitor is, they can be vertical, horizontal or 45 degrees, check which it is with some polarised sunglasses if you have a pair

 

[Ryne]

Seems so, Quite possibly yes.

Put a piece of white paper on your dashboard and see if the white square reflection is minimized or there is no change in the video.

Will do that in a minute, thanks.

that depends which way the monitor is, they can be vertical, horizontal or 45 degrees, check which it is with some polarised sunglasses if you have a pair

Used a non-3D TV as suggested before, would that situation still appear?

 

[OCD Tronic]

There is no universal standard how TVs are polarized so no way to be 100% outside the white paper on the dashboard real world recording test.

 

[jokiin]

Used a non-3D TV as suggested before, would that situation still appear?

yes

 

[DT MI]

Nice, thanks for that.

So mine's is installed incorrectly since it's clear when it's rotated 90 degrees and dark when it's horizontal (basically the colour of the lens is the opposite from the above picture)

Thanks, that is appreciated.

The only correct method of verifying CPL orientation is by checking reflections in your vehicle. Using any monitor, laptop, tablet, phone, etc. is suspect because you don't know beforehand how it's polarization is oriented.

 

[Ryne]

I did the paper test, and it looks like it was wrong before and is correct now.

If you want to see yourselves: https://www.dropbox.com/s/2m1u3xvgrea101c/2017_0708_182357_032.MP4

Thanks for the tips!

 

[OCD Tronic]

I did the paper test, and it looks like it was wrong before and is correct now.

If you want to see yourselves: https://www.dropbox.com/s/2m1u3xvgrea101c/2017_0708_182357_032.MP4

Thanks for the tips!

Now that you know which way it needs to be, and you're in the ball park, you can fine tune it perfect using your TV.

 

[DT MI]

Now that you know which way it needs to be, and you're in the ball park, you can fine tune it perfect using your TV.

I would respectfully disagree with this. Perfect alignment can be achieved in the vehicle in less than a minute with nothing more than a piece of paper. The CPL doesn't even have to be mounted on the camera - just view the reflections with the naked eye through the filter and rotate until the reflections are minimized, you now have the correct orientation.

https://dashcamtalk.com/forum/threa...nt-how-to-adjust-diy.15022/page-2#post-197505

From this thread to put it in context:

https://dashcamtalk.com/forum/threa...er-manual-adjustment-how-to-adjust-diy.15022/

 

[OCD Tronic]

Well if you have some specific problem area that's off center that you need more CPL reflection reduction for, yes you wouldn't want it exactly perpendicular and level.

 

[DT MI]

Well if you have some specific problem area that's off center that you need more CPL reflection reduction for, yes you wouldn't want it exactly perpendicular and level.

Sorry, but I don't really understand what you're saying.

Once you've oriented the CPL to achieve maximum reduction of reflections in the vehicle what more can be accomplished by playing around with a TV, monitor, etc?

 

[OCD Tronic]

If you fine tuned the CPL to be exactly 90 degrees, you know where you're at exactly. If you notice that you have more LED/Monitor reflections off center, you can fine tune the CPL a bit at at time in favor of that direction.

Not all dashcam owners have access to video out, and the screen is too small or too hard to see behind the mirror.

Sometimes you have to do things a bit at a time, trial and error. (and play back after)

If you use your TV to fine tune, what I'm saying is you know exactly where you're at and what should happen as you slightly nudge/spin from there.

 

[jokiin]

Sorry, but I don't really understand what you're saying.

Once you've oriented the CPL to achieve maximum reduction of reflections in the vehicle what more can be accomplished by playing around with a TV, monitor, etc?

from experience when (if) you adjust it correctly by eye it will match the adjustment on the computer monitor when rotated 90 degrees from actual