So I aimed my camera and took a few test shots hoping to be able to frame the stars of the Big Dipper and Little Dipper – which I was able to do as the picture above shows. However by the time the Iridium Satellite did its thing the sky was too bright for the ‘dipper’ stars to be visible as the (banner picture) shows. This picture used a 1-second shutter speed with the 18mm lens set to F8, and the ISO 200. Before my encounter with the Iridium 3 Satellite I spent about an hour taking pictures of Mars and the backward question mark shape of Leo; Jupiter and the Gemini Twins stars; Orion, and the Orion Nebula. These pictures were taken with a 55mm lens set to various exposure times and ISO settings. I was curious about how long of an exposure or shutter speed I could use without getting ‘star trails’, or a streak of light from each star as the Earth rotates. The picture of the Pleiades used a 55mm lens set for an 8-second shutter speed and there are noticeable ‘star trails’. This more or less confirmed what I had suspected and that a 6-second shutter speed was probably ideal – at least for my camera. So, while I was changing the shutter speed I also played around with the ISO setting and the aperture setting. Each of these had an effect that bears looking into further. Somewhere I’ll find the right mix of ISO, aperture, and shutter speed. But then the sky transparency is never the same so that right mix setting may be an elusive thing.
Click here to read about and see additional pictures of the ISS and Iridium flares.
Click on each of these thumbnails to see it full size.
Click here to go to the Qué tal in the Current Skies web site for more observing information for this month.