Video quality with 8 inch / 20 cm Lens Module Extension Cable

[Bob.Blockerlundt]

When I attach the 8 inch (20 cm) lens extension cable, I see more noise in the video, in the form of random white or pink pixels flashing on various parts of the screen. The video is still usable, but the issue is just something I noticed. When I remove the extension cable, video looks normal again.

For anyone else who has tried the 8 inch extension cable, are you seeing the same behavior?

I understand longer extension cables will naturally introduce more noise and artifacts, but I would like to confirm whether the degree of noise I am seeing is expected and normal. Or if I should try a replacement cable.

I captured some video samples to show the difference, but unfortunately, YouTube processing smoothed out many of the flashing pixels. You can still sort of see it, but the issue is more obvious in the original file format. Try viewing both videos in full screen, 1080p, and 0.25x playback speed. Look for the flashing pixels (or lack thereof) on the black backpack and orange couch background.

Video without lens extension cable:

Video with 8 inch extension cable:

 

[Bob.Blockerlundt]

I thought of another method to help explain the issue. I took some video with the lens cap on, so the expected result should be all black. Yes, this setup is a bit contrived, but it's just to isolate the symptom.

Results:

Without the lens extension, the result is as expected, all black.

With the lens extension, the result has the flashing pixels. Here is an example frame, with the issue circled:

Is this normal?

 

[barbagris]

Bob - this may sound a bit odd. Try wrapping the cable with tinfoil - this will act as a shield. Be interested in your findings if you try.

 

[roxor]

Bob.Blockerlundt, if you want to see a lot of pink pixels, mount it in the car and go for a drive.
This is how it might look:

From 13:00

 

[Bob.Blockerlundt]

Thanks all for the replies!

@roxor
Interesting video. I see what you mean by "a lot of pink pixels" when the entire frame flickers pink!
But for me, when I had it mounted in the car, the video only had a few sparkles and specks, here and there. It was not all pink all at once, as in that video from qasqdk.
Nevertheless, the problem may be related, and he may want to try the same solution... which leads me to...

@barbagris
Thank you for the suggestion! It works!

I started with a piece of aluminum foil the length of the entire extension cable, plus connector, plus lens module. I wrapped the entire thing, and took some sample video. What a drastic improvement. It seems that the flashing pixel issue is entirely gone.

So next, to narrow down the culprit further, I broke the foil into three pieces, and took sample video as I tested applying and removing each piece. The result is that the trouble spot appears to be the connector between the extension cable and the lens module. As soon as I wrap it, the flashing pixels are gone. As soon as I remove the foil there, the flashing pixels are back. I did not have to wrap the cable or the lens module.

I then tested how much foil was necessary to achieve the fix. My original piece of foil was 12 inches, but I found not all of it was needed.

So in the end, the solution was a piece of foil slightly larger than 3 inches by 1 inch, good for about two wraps around the connector. I covered enough to touch the extension cable on one side and the ribbon cable on the other, including the exposed green wires. Perhaps not all of that was needed, and I could have narrowed it down even further with some more experiments, but it was a small enough area for me. The main concern was that the extension cable and lens module did not have to be wrapped, so they are not bulked up.

I then wrapped the foil in black electrical tape, to make it secure and more discreet. This made me wonder whether electrical tape alone would have sufficed. However, I did not test it, and I kind of like having the foil under the tape to keep the parts free from any tape goo, in case I want to change things up in the future.

Anyway, problem solved!

 

[Deleted member 12503]

@Bob.Blockerlundt , did you use something to isolate between the connector and foil?
Thnx,

 

[Bob.Blockerlundt]

@Bob.Blockerlundt , did you use something to isolate between the connector and foil?
Thnx,

No, I just wrapped aluminum foil directly on the connector. Then black electrical tape as an outside layer.

Are you seeing a similar issue?

Are you concerned about isolating the connector from the foil?

 

[Deleted member 12503]

Thanks for your reply. I just received the Mobius and extension cable a couple of day ago so have not done anything with it yet. I was just preparing by reading some interesting experiences from others before I would begin modifying ;-)
Just wondered if the foil could cause shortage if applied without insulation...

 

[Bob.Blockerlundt]

Just wondered if the foil could cause shortage if applied without insulation...

Well, it seems to be working fine for me, but you do raise an interesting point. Maybe some extra electrical tape on the inside surface of the foil wrap wouldn't hurt.

 

[DashSplash]

No, I just wrapped aluminum foil directly on the connector. Then black electrical tape as an outside layer.

I had the same issue with my new Mobius C2. The aluminium foil trick solved my problem too. MANY THANKS !