Re: I messed up
Cracking a lens by spraying it with liquid gass is perfectly possible, and I'd guess that the effect could be reproduced pretty reliably with most optics.
The reaction by many people here is another example in the long line of misjudgements as to the cause and effect of damage to equipment. That "tiny little bit of liquid gas" doesn't seem spectacular, yet the thermal stress on the glass doesn't depend on the impressiveness of the incident. The only thing that counts is the fact that the gas induces a very steep thermal gradient in the glass because it cools it down locally and very quickly. If you cool down the complete lens evenly, there is much less thermally induced stress, because the stress is a result of one part of the lens contracting from the cold while the rest keeps its shape. Cooling down a lens locally at the edge very rapidly is kind of the maximum penalty in this respect.
The comparison with glass tableware really cracked me up (sorry for the pun), I wonder how people would like a scope made from those types of glass. Optical glasses are optimised for optical applications (who would have guessed?) and often glass types with very desirable optical characteristics don't like mechanical stress and thermal shock. There are optical glasses that are at risk of cracking when they are cleaned with cold tap water between grinding steps. While such fragile materials are not suitable for scopes anyway, this illustrates that the problem is very real and that any technical material is a tradeoff between different properties.
A realistic scenario for thermal shock in riflescope application would be jumping from a plane (high altitude, low temparature) into warmer air or worse, water, or moving from a warm building/vehicle into the cold. Of course this kind of stuff gets checked when people like the USMC evaluate a scope, but as I said, none of this comes close to spraying the lens with liquid gas. You could as well hit it with a blowtorch, and scopes are just not designed for stovetop use.
Clinto, you will have to send the scope in to get it fixed. You might want to get hold of
Paul if you want to know what to expect in advance. While this is certainly not a warranty issue, changing the objective isn't that big of a deal and you may get away cheaper than you might think.
