This image was created entirely in the camera - a triple exposure - about 10 years ago, and was recently scanned from the negative. Photoshop was used to do a little cropping and contrast enhancement. The three exposures: The Stars - back-lit black paper with pin holes The Clock The Armillary Sphere Total exposure time for this image I can't recall, but am certain exceeded the 4 second requirement. I also made this particular armillary sphere. They're really cool devices and what you end up learning about, in order to set one up properly, is quite interesting. This particular design of mine allows for the easy adjustment for any location (latitude and longitude) in the northern hemisphere while also being able to compensate for the equation of time and daylight saving time. When properly set up, direct readings can be made to the nearest five minutes (of time) with minutes easily estimated. If you're interested in learning more about the armillary sphere, check out these links: Smithsonian Air & Space Museum University of Cambridge