The most obvious effect of low temperatures on DSLRs is that there are a lot fewer hot pixels. This is a good thing and is why astronomical CCDs are internally cooled. It's also why we take dark frames at the same temperature as the exposures from which they are to be subtracted.
A second effect, not so benign, is that batteries lose some of their capacity. If you remove a "dead" battery from a camera and warm it up in your hand, it will often come back to life. LCD displays may also lose contrast in the cold, but the effect is temporary.
At temperatures down to about 0° F (-18° C), those are probably the only effects you will notice. At lower temperatures, though, electronic components may begin to malfunction. Those most likely to be affected are flash memory devices and data communication chips because they rely on voltage thresholds that can shift with temperature. This means your camera memory card may have problems, as well as the flash ROM, USB port, and serial port of a microprocessor-controlled camera or telescope. "Microdrives" (tiny disk drives built into memory cards) are not rated to work below 32° F (0° C).
Do not bring a very cold camera directly into warm, humid air, or moisture will condense on it. Instead, put it in a plastic bag, or at least a closed case, and let it warm up gradually. If condensation forms, do not use the camera until it has dried.
Was this article helpful?