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Double vision (ghosting) at night through windshield?

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I'm not an ophthalmologist (but I did date one once), but I did get a degree in Physics and I've had a number of semesters with optics (albeit, it was 20+ years ago).
If you're looking for an explanation, I think the most likely cause is refraction/reflection due to the windshield being made up of multiple layers.

The windshield is likely a sandwich of multiple layers of glass and plastic (e.g. tint, UV film, etc.). Refraction occurs when light passes through different mediums. What's likely happening is the light is being refracted, and then some is being split and reflected (probably twice) and forming the ghost image above/below the actual image.

During the day, there isn't enough contrast to notice the issue, but at night headlights and streetlights have a very high contrast that makes it very obvious.

The relative angle of the windshield would also be a factor.
 
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Like vandacca said. Any time light goes across an interface like air/glass or glass/air, there's a slight reflection. Purposeful optics like camera lens and binoculars use all sorts of fancy coatings to reduce that behavior.

So if the glass is at an angle, the reflection off the second glass/air crossing (ie the one into car) keeps a fraction of the light inside the glass which then zigs upwards (given typical slope of windshield) to the outside glass/air which it does same thing again but returns to same original direction, and most of that then enters car offset slightly from original ray. THe process repeats and you'll get many multiples but each is only a few percent as strong as the primary ray.

I looked last night and saw it clearly on my Model S when I knew what I was looking for. Usually people just tune it out.

Hmnm, I haven't tried it, but you might take one of those laser pointers and have someone shine it into car onto piece of paper and then look at what happens. I bet you'll see a set of dots.

Windshield.jpg

And there's no way to 'fix' this short of putting anti-reflection coatings on entire windshield. Its a fundamental property of optics, and has been happening on all windshields since they were invented. Though there might be something with the Model X's unique windshield to make it more noticeable.
 
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Model X owners who don't think the windshield is reflective can shine a flashlight towards the sides. From the front seat, you will see the wires and bolts reflected from the inside of the pillars. The direct view from the front of Model X is even more revealing. Nothing is hidden.
 
Thanks for the great diagram @mfel. Yet another variable in the thickness of the windscreen. The thicker the windscreen, the greater the separation. I suspect that one reason for the more pronounced effect on the Model-X is that the big windscreen has to be thicker for safety, plus the steep angle for aerodynamics.

Anyway, there may be an anti-reflective coating that may help to minimize the effect.
 
New Model X owner here, took delivery 3/30. Not sure I would have noticed if I hadn't seen the title of this thread. Thanks guys! :/

But can confirm the same, and I pointed it out to my wife too, who may also be unable to unsee now... Kinda eager to see how this goes...
 
New Model X owner here, took delivery 3/30. Not sure I would have noticed if I hadn't seen the title of this thread. Thanks guys! :/

But can confirm the same, and I pointed it out to my wife too, who may also be unable to unsee now... Kinda eager to see how this goes...

Congrats! Did you notice any other quality issues with your X? Did you get a sunshade?
 
Congrats! Did you notice any other quality issues with your X? Did you get a sunshade?

Thanks!

No sunshade, but confirmed with rep that I would eventually be getting it. Only other issue I'm experiencing is the driver side middle seat doesn't move forward like it should for 3rd row access, but I'm thinking this may be due to a car seat issue...

Reading more of this forum tho, is opening my eyes to other potential issues... ignorance is bliss....
 
Can anyone who has tinted their front windshield say whether this improves or worsens the effect? Thinking about getting Photosync on the front.

Interestingly, the shop I asked for a quote from said they have done several Model Xs, and they require a waiver for the front windshield application; they say other shops have cracked it during install, and that they are not sure of the structural integrity due to size and curvature.
 
Hello all,
Here is the latest update: I stopped by my local SC in PA today and spoke to one of the SC mangers who told me that the issue had been elevated to an internal topic @ Tesla. He also said he was able to see the problem himself during low daylight on another model X. I offered to loan my car back to Tesla in case they needed to have a real subject for night time problem testing. Bottom line is that 10- Tesla acknowledged there was a problem 2)- there were a few more faulty windsheilds out there and 3)- they had pulled the record for my car's windsheild to see where it took them. After I heard that they would be looking for a permanent fix, I decided to hold off on a replacement request at this point and get one at the time of my first appointment with Tesla at the end of April.

One final note: not all ModelX windsheilds are affected; most likely Tesla will be looking for common denominator among the reported cases. I strongly suggest that you let Tesla know immediately if your car is affected. Hopefully this enables them to identify the bad batch (design/manufacturing/material flow) fast. Otherwise, we will be getting windshields after windshields and it will be a random luck of the draw when we end up with a "normal' one.

Thanks,
Farzi
 
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Has anyone definitively confirmed that there exists Model X windshields *without* this problem? (ie has someone who knows the problem and can see the problem ever seen a windshield without the artifact?) I also picked up my car at Palo Alto, so I will register my desire to get a new windshield (after redesign).
 
@proven, It is impossible to miss the light effect at night when cars are approaching on the other side, specially on a two way street. The same goes for the traffic lights. If you look at the pictures posted, you'll see what we see. So it seems to me that you have one that functions as designed. I also don't believe it is a bad engineering, I am more inclined to think it is a bad manufacturing batch. Not all cars would be affected, otherwise it would have been noticed by Tesla's team.
 
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I haven't noticed double vision yet, but I haven't looked for it either. I'm not sure I want to!
What has been seen can never be unseen. :)

FWIW even after I was aware of it, I or my wife never noticed it. I have not told her about it yet and I only started to look for it when I was bored and sitting at a supercharger the other night and saw it in the street lights. Seemed to me to be more pronounced at the edges of the glass. Did not notice it or my brain filtered it out in the direct viewing area.

So now I am going to have to spend all of my night driving time staring down these abhorrent images.:mad: