Solar Telescope - Cross Section
A simple solar telescope, constructed by Nick Porcino and me as a follow-on to his Advanced Solar Telescope Mark I. The barrel is made from 3" poster tubes and contains two lens elements. The focal length of the device is about two meters. The image of the sun is projected onto a screen at the rear end of the telescope. The resolution of the projected image appears to be about 25 arc seconds, good enough to see larger sunspots. Click here to see a sample image shot with an iPhone 4.