Looking for advice from folks who have real-world experience using DSLR plus telephoto lens for wildlife in cold temperatures.
I have two 7D mk II cameras, and Canon 500mm f4 IS II (and 1.4x). The camera is listed to operate in temperatures down to 32 F. I can't find reference for temps for the 500mm.
What I've noticed on a few occasions when going out in very cold conditions around freezing temps (in some cases hovering above freezing, sometimes below freezing, and in some cases perhaps closer to 28 F) is that my rate of well-focused wildlife images is very low. For example, with owls in flight, the properly focused rate is something like 1%. Also, some images seem to overall just seem soft, like there is some kind of haze over everything (I deleted all of the shots already since this happened at least a month ago).
I did try changing various settings on camera, including AF settings, but nothing seemed to work. I believe this has also happened with both of my 7D mk II bodies.
Anyway, I was wondering if anyone else has had similar experiences (again, with telephoto lenses and similar equipment, and moving subjects, in cold temps). If so, any ideas what exactly is causing the AF issues, or the fuzzy looking images? Camera malfunction due to the temps? Would using the camera in temps below its rated 32F cause these issues? (also, could these temps permanently damage the camera?) Expansion of electronic components, optical alignment, or image sensor issues due to cold? Does the lens have lubrication inside that is perhaps sluggish due to the cold? I'm grasping at straws here.
I will say that, as far as I can recall, I have NOT had similar issues in warmer temperatures (for example photographing bald eagles in July)
Thanks for any insights you can offer.