Hello all,

Some cool information regarding the side windows.

I ran some tests with a calibrated light meter on my side windows and windshield. The Windows I am referring to are "UV" treated glass.

All testing carried out on slightly overcast skies to provide even light scatter.

I held the meter probes against the window, read a value. Then opened the window and read the value in the same position.

Probes used: white light sensor and UV array sensor.


Results: window closed/open

Side windows
White light: 25.3/34.6 kLux (~70% Transmittance)
UV light: 1.072/9.44 W/m^2 (90% UV Absorbance)

Windshield
White light: 33.5 kLux (~3% Transmittance)
UV light: 85.5 mW/m^2 (99% UV absorbance)

Turns out our 3IS windows are tinted and do absorb most UV radiation in both UVA and UVB form. Now, the 10% Transmittance of UV energy is negligible and I will later explain why (in a following post).

What was interesting to me was the 70% tint on our windows... Dealer said it was 90%. Good to know. More fun stuff later.

Also, I'll post pictures.

* Update: Windshield is not 3% Transmittance, it's 97%. However, this number is weird to me and I don't think it's accurate since I didn't get a guage on the ambient light without the windshield. Also, these numbers are just where I found the readings to be most stable, there's about a 3% variation due to user error.





Side window closed UV





Side window open UV





Windshield UV





Side window close white light





Side window open white light

 

Really though you want heat reflection, so it needs to block Infra Red. I had lumnar 30% all around and worked great, specially with late afternoon summer sun heading northbound on the highway.

 

Yeah IR blocking is only achieved by Ceramic or Crystalline film. Both of which I have had my eye on for a while now. When the film is too dark, it'll actually absorb some heat and radiate it inside... Like how a black car would. The darkest I want to go on the back is 40%... With 60% on the front.

 

Got the llumar ctx 30 all the way around (other than the windshield obviously) on mine. It's ceramic and the reduction in heat from an open window vs the tinted window is pretty crazy in the direct sun. FL legal is 28%...installer put on the 30% and later metered it after it was installed and it measured about 21.5 which makes sense. (30% film x 70% window = 21) It's an ideal shade I think because it doesn't hide the Roja red under Ultrasonic Blue 2.0

 

The windows are normally factory tinted.

Have a look at my post which has the actual tint numbers for both 2IS and 3IS.

https://www.clublexus.com/forums/is-...ml#post8084494