GT680W Remote-lens mod and polarizing filter

Iulian

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Jan 8, 2014
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Location
Brussels
Country
Belgium
Dash Cam
Viofo A129 Duo GPS, Dual Mobius B-Lens
Hi guys,

As Niko asked me over here, I'm opening a thread about my remote-lens mod. Meanwhile, I've also "made" a polarizing filter for my dashcam, so I'll talk a little about it too.

Even though the GT680W is a fairly small dashcam, I've always hated the idea of having things "hanging" on my windshield. So I started looking for a solution.
While searching, I saw Techmoan's video about the Mobius lens extension cable and thought it was an excellent idea.
I opened my dashcam and got pretty excited when I saw that the lens had a ribbon-type connector. There was a problem though, the Mobius ribbon connector has 26pins whereas the GT680W's only has 24.
I searched for a few hours and found a lens extension cable for the 808 #16 key-chain camera that had 24pins.
"What the hell, it's only 6$, I might as well give it a try..."
There were other cables, longer ones, but I preferred to be safe and bought the short one. (8")

The cable arrived after about 3weeks (I live in Belgium). Opened the camera again, tried the cable and.... YES! It worked.

CU8c6DO.jpg


I then tried to make a lens housing that would absorb most of the vibrations. I used the high-density foam that was in the GT680W's box.

Here I was trying to figure out the best shape:

ligwSut.jpg


I ended up with this:

03e0NY7.jpg


I made 3 grooves on the top of the housing so i could insert the GoPro Quick Mount. It was already pretty solid like that, but I added some super glue just to be sure.

This is the final result:

1c119rn.jpg


If I need to use my camera with a different vehicle, the GoPro flat mount is attached to the windshield with double-sided adhesive tape and I only have to slide out the quick release that has the lens housing attached to it. It takes no time at all.

700_clip.jpg


The GT680W body is attached to the windshield's dotted area with 3M dual lock fasteners so it is invisible from the outside and can also be easily removed if needed.

I can slide the lens out of the housing very easily and put it back in the camera if I ever need it.

Positioning:

I first tried to mount it behind the black dots at the top of the windshield, but the housing that surrounds my sensors/rearview mirror cables is too long and goes really far down the windshield. If I mounted the camera behind the black dots I would capture a big part of that sensor housing in my videos.

So I mounted it in the center, on the sensors/rearview mirror housing but there were some vibrations. Minor, but they were there. Even though the camera was a little less visible from the outside than now, I changed the position.

7qIsMqE.jpg


Now I mounted it directly on the windshield, just under that housing so there are no vibrations at all.

0fksEil.jpg


We can see the Gopro adhesive mount from the outside a little bit, but it's really hard to tell what is going on.

DY2SY2b.jpg


cX6lpba.jpg



The polarizing filter:

A few weeks ago, I also made a polarizing filter that fits the shape of my lens housing.
I bought a 5x5cm linear polarizing sheet on ebay, cut it so that it matches the shape I needed and then glued (with a really tiny drop of super glue) a little piece of metal to it.
The box of the GT680W had two small magnets that held it closed. I used one of them and glued it just above the lens, on the lens housing.

Now, when I aproach the filter to the lens, the magnet does its thing and holds the filter. I can shake it really hard and it won't move.

Here is a video explaining it:

*I used a black marker to hide the super glue around the magnet. In the video it looks like it's really shiny, but it's not. I guess it was still wet.

And here's a video that shows how the camera works with and without the filter.


I'm quite happy with it.

Thanks for reading all that. :)
 
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looks like a good job.:)

how were the I bought a 5x5cm linear polarizing sheet on ebay, cut it so that it matches the shape I needed angled? At right angles to each other? Or . . . ?

Yes, right angles.
hold it straight - you see the effect
rotate it 90° - you don't
rotate it 180° - you see the effect
rotate it 270° - you don't
 
Yes, right angles.
hold it straight - you see the effect
rotate it 90° - you don't
rotate it 180° - you see the effect
rotate it 270° - you don't

So it appears that two linear polarizers at 90 degrees to each other, work as well as one properly set up CPL:).

this makes me think that this system may allow for a filter setup system, that can quickly removed or setup. Without having to go through the hassle of resetting the CPL each time it's re-attached.
 
So it appears that two linear polarizers at 90 degrees to each other, work as well as one properly set up CPL:).
"two linear polarizers at 90 degrees to each other" will allow zero light through!

A CPL is a linear polarizer which converts the output to circularly polarized light, normally only needed for SLR cameras, for most dashcams it will give the same result as a single linear polariser.

You don't need to adjust a CPL every time it is fitted, mine has a mark on it which if you place it at the top means that the linear polariser part is vertical - the setting you want.
 
You don't need to adjust a CPL every time it is fitted, mine has a mark on it which if you place it at the top means that the linear polariser part is vertical - the setting you want.

which is fine, if you can only fit it exactly the same place every time. I haven't seen a system capable of that,yet
 
which is fine, if you can only fit it exactly the same place every time. I haven't seen a system capable of that,yet

I tried this polarising film and you can literally throw it at the lens from 50yards and hit the right spot as if cut in a square opposing sides rotated 180 will work either way and you don't have to be particularly accurate !!

only down side is you do lose clarity of number plates but I ve never used a proper Cpl so wouldn't know if was any worse ....


Loving the lens mod and didn't expect it to be so small compared to the g1wh and have decided to do the same with a longer cable ideal at the rear of the car..

https://www.ebay.co.uk/itm/321181256035
 
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