Re: moon photos : What prevented the film emulsion in the camera used on the moon from freezing and cracking, or simply becoming insensitive from cold? Is film resistant to such extreme cold? What about when the camera was held in the sunlight several minutes, wouldn't the camera turn into a miniature oven?
The cameras had no contact to the hot moon surface, direct heat flow from solid to solid was not possible. Moon has no atmosphere, heat transfer by gas was impossible too.
The special modified Hasselblad cameras and the film magazines used on the moon had a silver paint finish to minimize heat up by sun light. The cameras were not filled with a gas, that reduced heat transfer from camera surface to film inside the magazine.
Foto film does not become insensitive from cold. There is a method for long time exposure with cooled film for better sensitivity used for astrophotography. Therefore no heating was necessary.
The cameras were used during the lunar day, so overheating was more of an issue than the film getting too cold. As Uwe indicates, the outside finish on the camera kept temperatures from getting too high.
The Data Camera was given a silver finish to make it more resistant to thermal variations that ranged from full Sun to full shadow helping maintain a more uniform internal temperature. The two magazines carried along with the Data Camera also had silver finishes.