IMPORTANT NEWS: National Electric Vehicle Sweden has agreed to buy the assets of Saab Automobile and the sale is expected to be finalized during the summer.

Sunday, January 2, 2011

The head-up display through sunglasses

With the new Saab 9-5, Saab does of course for the first time offer a head-up display (HUD). The HUD displays information such as speed, rpm, temperature, navigation info etc. on the windshield. A HUD consists of a computer that sends the information to be displayed to a projector unit, which displays the information on a reflective foil or coating which is on the windshield. But how does wearing sunglasses affect the visibility of the projected image on the windshield? And especially how does wearing polarized sunglasses affect the displayed image?

So earlier today I decided to take some pictures to show how sunglasses affect the HUD image. The brightness of the HUD in the Saab 9-5 can be adjusted (as well as turned off) with a switch. There are 10 brightness levels available. I set the brightness to level 5, i.e. the average brightness, before I took the pictures below.

Here's a picture of the HUD as seen without wearing sunglasses:

And a picture taken through Ray-Ban "ordinary" sunglasses:

And finally a picture taken through Polaroid polarized sunglasses:

Polaroid's polarized sunglasses are supposed to block glare or reflections. Polarized sunglasses are also known as anti-glare sunglasses. From the pictures it is obvious that the Polaroid sunglasses do a good job, as they eliminate the reflection of the HUD!

 So does this mean that if you use anti-glare sunglasses you can't see the HUD at all? Well, the visibility if the HUD is definitely reduced, but if you adjust the HUD to full brightness, then the visibility gets better.

Here a picture of the HUD at full brightness taken through polarized sunglasses: