glass roof - production change (July 2018)?

[Stellavator]

Hahaha

But what about those half and half ones?

Right! What about the half and half? The whole argument about this being a different vendor using different film is BS. Why on earth would a vendor use one film on half of the same piece of glass, and a different film on the other? Makes no sense. This is something deliberate, and we are seeing the gradual phase out of the film that causes the red color.

And, I think they are wrong about this being the UV film. Why does no other car have this? Why not the sides? I think it's the IR, and they are either phasing out the colored film to a non-colored film, or phasing it out completely.

My brother is an optical physicist, and I'm going to get his take on this. Will report back.

 

[Garlan Garner]

My theory? Thus far, every picture showing the color shift on the entire rear glass is a car with tinted windows. I think the rear glass is always all or none (well, except for that car that had a blotchy look a while back). The reason you don't see the color shift going all the way down on untinted cars is contrast: the light shifted from IR to visible and reflected is overpowered by the light you're seeing through the clear window. At least, that's my theory.

Tesla isn't going to spend money Tinting 6000 Model 3's a week. Neither are they going to pay the expense of tinting 24000 windows every month. If anything....Tesla is going to cut as many costs on the Model 3 to increase its profit margin and keep manufacturing/production as simple as possible.

Tesla explains why it asked some suppliers for retroactive discounts

 

[brkaus]

My brother is an optical physicist, and I'm going to get his take on this. Will report back.

I’m sensing a gofundme coming on to buy him 3 different model 3s to analyze.

 

[Garlan Garner]

Right! What about the half and half? The whole argument about this being a different vendor using different film is BS. Why on earth would a vendor use one film on half of the same piece of glass, and a different film on the other? Makes no sense. This is something deliberate, and we are seeing the gradual phase out of the film that causes the red color.

And, I think they are wrong about this being the UV film. Why does no other car have this? Why not the sides? I think it's the IR, and they are either phasing out the colored film to a non-colored film, or phasing it out completely.

My brother is an optical physicist, and I'm going to get his take on this. Will report back.

If a customer asks for something....then when the vendor supplies it.....its a marriage. The vendors job is to deliver what the customer wants.

It doesn't matter if it makes sense.

Example"
Tesla recently changed the tire ( not the vendor) of choice for the Model S. Pirelli didn't care. They just gave Tesla what they wanted.

Tesla is using Michelin's for the M3PD.... originally they said they were going to use hanhook tires but the vendor couldn't deliver the necessary grip. In this case....Tesla changed Vendors.

The Seat manufacturer changed the seats of the Model 3 a few weeks ago - Because Tesla wanted them to.... They just gave Tesla what they wanted.

You guys keep thinking that the color of the UV is a depiction of whether UV exists or not. Clear is a color.

 

[UltralightBeam]

Looks like you got your windows tinted based on your previous pic. Just curious, what tint did you go with for the rear? Did you have the orange coating effect prior to the tint?

It’s the same as what’s on the sides. It’s whatever is in the glass that provides that color cast. And yes, it showed orangy reddish before. I’m still waiting for the plot twist . I swear if the half and half folks really also have a HUD...

 

[Tezlah]

But what about pictures like this? :

That looks "fully coated".

Mine is only partially coated, like these:
View attachment 330266

The first picture is of a car with an aftermarket tint. This may be the visual difference

 

[Garlan Garner]

The first picture is of a car with an aftermarket tint. This may be the visual difference

Aftermarket tints are applied under/below/on the inside of the car - of the manufactured UV film.

 

[Garlan Garner]

As it stands right now....the color of the window(s) in each Model 3 is not at the request of us ( the customer ). It' not an orderable item.

For those who are still looking forward to your purchase/delivery.....don't accept the car if the color of the window(s) is not what you want.

Look over the ENTIRE car and don't accept what you don't like. If Tesla can't change your car to be what you want....then there will be a decision to be made.

The color of the UV ( including clear ) on all of the windows should be considered if that's important to you.

 

[nvx1977]

Sorry, but I think Garlan's Tesla sources are wrong. The red film layer is most likely an IR blocker.

Let's go back to first principles:

IR is infrared, which starts right beyond visible red in the electromagnetic spectrum.

IR blocking material generally isn't that precise and targets a certain frequency band in the EMS. That band may contain some visible red frequencies.

The goal of an IR blocking material is either to reflect or absorb IR (and minimize refraction) so it doesn't strike objects inside the cabin.

The material in question is likely optimized to reflect, since absorption would mean the glass gets very hot and is unsafe to touch and radiative heat transfer becomes an issue again(new IR waves are created).

If IR is reflected, and some visible spectrum is also reflected, it explains the red-to-yellow wavelengths that we can see.


Now onto ultraviolet:

UV is ultraviolet, which starts right beyond visible purple/violet in the EMS

UV-A is the band directly adjacent to the visible spectrum and is less harmful than the higher energy UV-B band.

UV blockers also target a range that generally tries to eliminate all of UV-B and most of UV-A. UV-C is a thing, but our atmosphere blocks it.

Because the band range doesn't extend across all of UV-A, any reflection on the blocking material generally won't be perceived as purple/violet, since the reflection didn't cover the visible violet area of the spectrum. Therefore UV blockers are usually colorless.

If a UV blocker is advertised as 100% UV-A blocking, there's a chance it will be perceived as purplish, since now there's likely some overlap into visible spectrum.


Knowing all this, it's very unlikely that a film that's perceived as red/yellow to our eyes is a UV blocker. But it makes perfect sense as an IR blocker. More specifically, an IR reflector.

IR heat transfer is radiative heat transfer and requires line of sight. This would explain the coating not extending all the way to the bottom edge in some VINs (like mine). It means no IR protection, but in an area that is hard for solar rays to have line of sight on passengers. I can't explain new VINs with no red on the rear glass. Either there is no IR reflection (and just absorption thru dark tint), or the IR band being reflected does not encompass any visible red spectrum.

 

[Stellavator]

Perhaps they began phasing out IR reflective film when they activated cabin heat protection?

Maybe they activated cabin heat protection BECAUSE they knew they were phasing out IR reflecting for cost purposes?

Hmmm.....

 

[OmahaG8]

PM3+ Drizzle today...
View attachment 330234

What are the first few digits of your serial VIN?

 

[dsvick]

Sorry, but I think Garlan's Tesla sources are wrong. The red film layer is most likely an IR blocker.

Let's go back to first principles:

IR is infrared, which starts right beyond visible red in the electromagnetic spectrum.

IR blocking material generally isn't that precise and targets a certain frequency band in the EMS. That band may contain some visible red frequencies.

The goal of an IR blocking material is either to reflect or absorb IR (and minimize refraction) so it doesn't strike objects inside the cabin.

The material in question is likely optimized to reflect, since absorption would mean the glass gets very hot and is unsafe to touch and radiative heat transfer becomes an issue again(new IR waves are created).

If IR is reflected, and some visible spectrum is also reflected, it explains the red-to-yellow wavelengths that we can see.


Now onto ultraviolet:

UV is ultraviolet, which starts right beyond visible purple/violet in the EMS

UV-A is the band directly adjacent to the visible spectrum and is less harmful than the higher energy UV-B band.

UV blockers also target a range that generally tries to eliminate all of UV-B and most of UV-A. UV-C is a thing, but our atmosphere blocks it.

Because the band range doesn't extend across all of UV-A, any reflection on the blocking material generally won't be perceived as purple/violet, since the reflection didn't cover the visible violet area of the spectrum. Therefore UV blockers are usually colorless.

If a UV blocker is advertised as 100% UV-A blocking, there's a chance it will be perceived as purplish, since now there's likely some overlap into visible spectrum.


Knowing all this, it's very unlikely that a film that's perceived as red/yellow to our eyes is a UV blocker. But it makes perfect sense as an IR blocker. More specifically, an IR reflector.

IR heat transfer is radiative heat transfer and requires line of sight. This would explain the coating not extending all the way to the bottom edge in some VINs (like mine). It means no IR protection, but in an area that is hard for solar rays to have line of sight on passengers. I can't explain new VINs with no red on the rear glass. Either there is no IR reflection (and just absorption thru dark tint), or the IR band being reflected does not encompass any visible red spectrum.

Well said! Just to add on, as has been mentioned before, the UV blocking is usually done by a film between the layers of laminated glass. That's why it is the windshield and back glass in cars that block UV - they are laminated while the side windows usually are not. So, assuming that the entire roof is laminated in the Model three, we can expect that the entire thing is blocking UV, the same as any other car manufacturer.
So, if the red tinted glass is most likely the IR blocker it is entirely possible that they've switched to a different blocker that reflects less of the visible spectrum. There a few other car manufacturers out there that offer IR blocking windshields and they do not have the red tint either, so just because it isn't there doesn't mean that it isn't working.

 

[Tezlah]

Aftermarket tints are applied under/below/on the inside of the car - of the manufactured UV film.

Correct. The dark tint applied on the inside of the car makes the red stand out more because it is less translucent.

 

[seattlite2004]

Here is a picture of a camera lens UV and UV/IR filter. It seems that the filter with IR coating iridesce more red than the other filter which is just UV.

 

[ergela]

Here is mine last night. It was the same pre tint as it is now. Tint did not change the "orange effect". The blank spot towards the rear just didn't have condensation. April mfg date.

 

[CCIE]

Discussions about UV blocking aren't really helpful. All modern automotive glass blocks UV. If it didn't, we'd all have sunburn from sitting in the car for hours.

IR is a different story. My guess is that they've switches to only applying IR blocking on glass that's over occupants' heads. That would be comparable to having a metal roof (sun's heat blocked from above, but not from front/back/sides).

 

[bandido]

The bigger question, that I brought up earlier is the noticeably higher amount of heat coming through the roof glass in a Model 3 vs S/X. I spoke with a local tinter here in phoenix, he said there is definitely IR on the 3's roof, but none on the windshield as with the S/X. Still does not explain the much higher heat transfer through the 3's roof

 

[bottomsup]

if they did indeed remove IR rejection what does that mean in reality? is that the reason i couldn't use AM radio?

 

[Garlan Garner]

Its surprising that:

If all windows had clear UV protection then there may not be a question that UV was present. Color the UV film....and now clear can't be a color.

The bigger question, that I brought up earlier is the noticeably higher amount of heat coming through the roof glass in a Model 3 vs S/X. I spoke with a local tinter here in phoenix, he said there is definitely IR on the 3's roof, but none on the windshield as with the S/X. Still does not explain the much higher heat transfer through the 3's roof

Sorry, but that local tinter is just flat out wrong.

Also...the Model 3 glass is NOT hotter than the Model S and X"s glass. That's just not true at all. I proved this with a heat gun in another thread.

 

[Garlan Garner]

if they did indeed remove IR rejection what does that mean in reality? is that the reason i couldn't use AM radio?

You have an AM radio?