Apple Watch Sensors Question (w/ Pictures)

[campingsk8er]

I went in to my local Apple Store today because I suck at this whole college thing and just didn't feel like doing any homework (plus its too nice outside). Anyway, this was my second try-on appointment that I had, with my first one being last Friday. During this appointment, I noticed that the sensors on the Watch Sport are different than on the Watch. Can anybody speculate as to why? I know that the Watch Sport has a composite back and the Watch has a ceramic back, but why else would they be different?? Is one going to be more accurate than the other?

I've also included a comparison photo between the 38mm, 42mm, and the Pebble for anybody that wants them, and some of the details from the settings app on the demo models just in case somebody was looking for that as well. Sorry those are sideways!

 

[JerryCooke]

I didn't take the chance to look closely at both sets of sensors when I was in store today, though I'd assume that they work in exactly the same way - two are visible light and two are infrared. The difference, as I understand it from the design notes, is that the steel model has sapphire lens covers, where as the sport just has optical polymer.

Basically, I'd assume that the metal rings are surrounding the sapphire lenses, in much the same was as they're mounted around iPhone camera lenses. Since the back of the sport watch is polymer anyway, the lenses are presumably incorporated into the back plate and therefore don't require said rings. As far as accuracy goes, hmm, sapphire is a more optically perfect lens type than polymer (there's a reason camera lenses are glass on everything but disposable cameras), but given they're reading reflected light, I wouldn't think it would make much difference beyond scratch resistance.