I had my M8 in my convertible today. I had the top down all afternoon. The camera didn't miss a beat even though it got down to the 80’s today.
So there we have it - the M8 can handle January weather from minus 12 and snow to a cool sunny 82 in the same day.
What's a convertible? You don't see too many of hem up here, enjoy the nice weather and how about sharing some with us.
I had mine out for 4 days in averge 30' weather. We were camping so the camera never really warmed up much. Overall I saw about an estimated 50% decrease in batt life and one night we were out using the M8 as a flash monitor for the RZ67 at about 15' ambient + 25mph wind and a newly recharged battery lasted about 8 frames! I think I found the "too cold" line 🙂
I have used the M8 a bunch outside at 30' or so wth no issue but it has always been inside and warm then gone outside for a few hours. My 100% unscientific test tells me that the batteries do not like prolonged exposure to cold and start to degrade quicker as they stay colder longer even with recharge cycles.