TC's have temp ranges?

According to the manual, my TC has an official working temperature range down to -10C. Does anyone here know why that is? I haven't noticed that my other equipment has such a range. Where's the difference?

I'm planning on using the TC this weekend, and based on the weather forecast, I should probably be prepared to -13C. Should I be worried? Of course, I've read some older threads on NPN about photographing in the cold, so I think I have the battery and condensation problems in check. It's just this "TC temperature range" I'm confused about. My whole system, including the TC, are splashproof, if that makes a difference (probably not).

Thank you for any advice.

I wouldn't worry about it. Matter expands and contracts with temperature, and these minute variations may affect the accuracy of optics. This is also why very long lenses sometimes allow turning the focusing ring beyond infinity. The differences will be minute and if you close down your aperture a couple of stops from its largest setting, I highly doubt you will notice any ill effect.

Guy

I've used my Nikon TC-17E in temperatures as cold as 40F degrees below zero with no problem. (In Celsius, that converts to 40 below zero.)


Kent in SD

I also use my Zuiko 1.4 and 2.0 teleconverters down to -45 F without problems. At some point, I suppose, there is a risk of differential contraction from the cold and physical damage. Glass and metal have different coefficients of contraction, for example.

I have had focus motors quit because differential contraction pulled the juice away at contact points. Gold has a very high coefficient of contraction. But it's always worked again when it warmed back up.

Thanks guys!