Since I am feeling like getting involved again here's a late addition. From a recent trip to Boulder, CO on the road up to Rocky Mtn National Park. Using Impossible PX600 UV+ film. I discovered that the extra UV at altitude (this image was shot around 9000 ft) likely causes some serious overexposure, but I kind of liked this one. I didn't have a UV filter to put on my SX-70 so I couldn't confirm my suspicion.