Today the temperature was +96 Fahrenheit here in flyover land - I can't imagine how hellishly hot it must be in places like Texas, Alabama, Mississippi, Louisiana and Arizona right now.
This brings me to the topic of my post - the effects of hot temperatures and climates on cameras and lenses. When I worked in a camera store, every summer I would have people bring in cameras and lenses that they had roasted by leaving them in their cars for hours on end in 80+ and 90+ temperatures. Not smart.
The most obvious giveaway would be stopping the lens down to f/16 and finding that the aperture blades looked like they had been coated with baby oil or Vaseline. The cause of "oiled aperture blades" is this: Lens aperture blades are lubricated with dry lubricants. Roasting them at high temperatures causes the lubricant to change states and look like baby oil, which gums up the aperture blades and slows down their functioning. This can be repaired by sending them off for a CLA ( clean, lubricates and adjust) - an inconvenience and expense that could be easily avoided. Extreme heat can also affect the cement used to bond lens elements together in the element groups of a lens, causing the cement to fog or become cloudy.
Heat will also damage camera bodies. There are twelve different types of lubricants used in a Leica M film camera body. When a camera is left in a car during hot summer weather, the lubricants used become overheated, changing their state and/ or viscosity, allowing them to drain away from the parts that need them, leaving the parts insufficiently lubricated and allowing the lubricant to displace onto other parts in the camera which they are not intended for. A camera that has been baked in a hot car and used afterword can end up with damage due to insufficient lubrication of the moving . Again, this can be set right by a CLA - or it can be totally avoided to begin with.
How hot is too hot to leave cameras and lenses in a parked car? My rule of thumb is this: If it's too hot to leave a pet or a child in the car, it's too hot to leave your camera gear in the car. Another way to gauge whether it's too hot is this : If it's too hot for me to sit in my car with the windows up and not be uncomfortably hot, I won't leave my cameras in the car. This means that the mid 70s Fahrenheit s about the cutoff point.
This does require some planning in hot weather. Sometimes I have a cooler in the car with two or three frozen blue ice packs in it. I put the camera bag in the cooler and the blue ice packs keep the temperature in the cooler (and in the camera bag) at a safe level. Sometimes I carry a smaller camera bag and less gear so it is easily carried with me into the grocery store, Target, the bookstore or where ever I may be going.
When the outside temperature is in the 80s to 90s or higher, the temperatures inside an auto that is sitting in the direct sun can be 50-60 degrees hotter than the outside temperature. The temperature in a car trunk can soar as high as those inside the car's passenger compartment so leaving the camera bag in the trunk is not the answer, either.
Some would say that my precautions are a big pain in the ass. I think heat damage to my cameras and lenses is a much bigger pain in the ass - one that can be avoided by a little prior planning.
_________________ "Summer grasses - all that remains of warrior's dreams."
-Basho Matsuo
Last edited by Messsucherkamera on Tue Jun 19, 2012 11:57 am, edited 3 times in total.
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