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ok this has been lingering in my mind for a while, but why do Omega sell watches with no AR, then others with AR only on the inside or AR on both sides?

what is the deal with this madness? :think:

:-d
 

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ok this has been lingering in my mind for a while, but why do Omega sell watches with no AR, then others with AR only on the inside or AR on both sides?

what is the deal with this madness? :think:

:-d
That's just it .... it's madness. :-d - David
 

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My take on this is that it is not clear that AR is better than straight sapphire. While AR makes a watch easier to view under certain conditions it is also infinitely easier to scratch than sapphire.

Depending on the application and likely level of abuse AR makes more or less sense.

The simple fact is that AR on the inside is solving a non existent problem. Only AR on the outside makes any appreciable diference in my experience.

Personally I would only want AR in a tool watch used in situations in which it could be critical that I could tell the time first glance every time: pilot's watches for example. In all other situations I would want my sapphire uncoated as it is nearly impossible to scratch that way.
 

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The simple fact is that AR on the inside is solving a non existent problem. Only AR on the outside makes any appreciable diference in my experience.

funny I never considered that before, esp. given my interest in astronomy and optics. The only thing inner AR can do is block light reflecting off the dial. I wouldn't think that's a major source of reflection. Light has to hit the coating before it passes through the glass surface. Too bad they've not developed a harder AR coating because outside AR is what you want. Maybe some people enjoy reflections off uncoated sapphire but I think most of them (probably myself included) turn a defect--or undeveloped technology--into a virtue.
 

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I guess my point is that I will take reflections over scratches - reflections are far easier to remove! I suspect that developing an AR coating that is as tough as sapphire may be a bit tricky.
 

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I guess my point is that I will take reflections over scratches - reflections are far easier to remove!

exactly
 

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I never saw the need for AR coating until I got the Carrera chronograph...refection city. It's pretty awful. It doesn't "bother" me, but seeing some watch crystals disappear and the Carrera reflect anything and everything is a bit disconcerting.
 

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funny I never considered that before, esp. given my interest in astronomy and optics. The only thing inner AR can do is block light reflecting off the dial. I wouldn't think that's a major source of reflection. Light has to hit the coating before it passes through the glass surface. Too bad they've not developed a harder AR coating because outside AR is what you want. Maybe some people enjoy reflections off uncoated sapphire but I think most of them (probably myself included) turn a defect--or undeveloped technology--into a virtue.
Any time light passes from one medium to another, with different indices of refraction (air-glass, air-sapphire, water-glass, etc.), it causes a reflection, regardless of the direction of the light.

If you look carefully at a bright reflection in an ordinary pane of glass, you can see that there are actually two reflections, one from the front surface of the glass, and one from the back surface.

So, the crystals that are only coated on the inside really do reduce the brightness of the reflection that you see by about half.

I have a "cheapie" Tissot that has a crystal that is completely uncoated, and you can definitely see a difference between it and the crystal on another watch that is coated on the inside. If you look closely at a bright, specular reflection on the "half-coated" crystal, you can see the light source, plus a faint blue reflection. If the coating weren't there, the secondary reflection would be as bright as the first, doubling the glare.

My $0.02...
 
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