Once you remove a wet pumpkin for display, you should immediately dry it off. This prevents mold from hanving a chance to grow. Lighting the Pumpkin For professional quality photographs, you want to use an electric bulb in the pumpkin. A 40 watt, uncolored bulb on a electric cord works very well. Keep the bulb low or off to the side so that it illuminates the inside back wall of the pumpkin.
Some people suggest using a simple seven watt bulb or two to three candles.
I prefer the Tim Allen approach. It is important to scrape the back of the pumpkin to make a smooth surface so that no odd shadows are cast. Photographing the Pumpkin With the pumpkin lit, ideally in a mostly darkened room, take a picture of the pumpkin without using a flash. 400 ASA speed film works well, you can use 200 ASA if you let the shutter stay open longer. For really good shots, mount the camera on a tripod and use a zoom lens.