I have my lens resting on shelves in my office, dry and sunny. Most concerned about fungus not that it is risky in the environment I have them in but is it better to let them rest horizontally with the lens cap off so light will be on them during the daytime? I have usually have the lens upright, resting on the rear lens cap and with the front lens cap on so dust doesn't settle on them.

My main concern is that having the front lens cap on makes fungus more likely and I don't know if storing the lens horizontally does anything to the shutter.