Hello List, just saw the first aurora in my life. It was very pretty, but at least as much educative. Here are the lessons learned:
I have been looking for a geomagnetic storm since I came to Finland, checking the monitoring site (http://www.sec.noaa.gov/rt_plots/kp_3d.html) almost daily. As the gray-steel skies started to break up at the sunset today, I rushed to the city to buy rolls of Provia 400F, one of the films generally recommended for aurora photography. Being young and naive, I set out to photograph the lights right after twilight at 5pm. My idea was that aurora would dance over the sky for the whole night, only to disappear with the first rays of the dawn. :) After more than two hours of stumbling through the scary dark forest and catching cold by the lake, I packed up and went home. Of course an hour later, the lights did appear. Rushing to the lake again, I lent my tripod to a friend to play with and went looking for The Perfect Composition. By the time I found it, the sky turned dark again. Puzzled, I approached a seasoned (or so it seemed) aurora photographer on the scene. He explained that aurora usually passes our latitude from 10pm to 11pm going down from north to south. It returns after midnight at 1am, going back north again. Apparently, it is one of those things everyone but me knows. ;-) It has something to do with the position of sun, he even carried a PDA to check the angle at which the solar winds hit the atmosphere. I then inquired about the exposure times. What he used is very inconsistent with the resources on the internet (http://www.ptialaska.net/~hutch/aurora.html, http://w1.877.telia.com/~u87717747/english/bildarkiv_4.htm and more), where they talk about 400 speed, fast lens and about 30 second exposures. He was using f2.0 lens, ISO 50 and about four seconds! My friends digital camera had the right exposures at ISO 100, f2.8 and 8-15 seconds. Anything longer and the photo was blown out. And the aurora was supposedly on the faint side. Sorry for the long post. :] I would like to hear comments of experienced aurora photographers, anyone? Mike (http://skwid.wz.cz) ________ Svetova kniznica SME - literarne klenoty 20. storocia - http://knihy.sme.sk
