详细说明来了 :arrow:
Object ................................... The Southern Cross (Crux)
Name .................................... -
Date + Time .......................... May 23, 2004 / 0:00 UT
Location ................................. Farm Okumitundo, Namibia
Optics .................................... Hasselblad/Carl Zeiss 4/120mm
Tools ..................................... -
Detector ................................ Kodak Ektachrome E200 Prof. 6x6 cm
Exposure Time(s) ................... Approx. 30 minutes
More Details ........................... -
Mount .................................... Fixed mounted on a photo tripod
Guiding .................................. -
Processing Details ................... PhotoShop
Notes ..................................... I focussed this image progressive. I started with a totally defocussed setting. During the exposure, I changed the focus every 40 seconds in 'infinity'-direction. Before the end of this sequence I covered the lens for approx. two minutes before I let the light pass again for about 10 seconds. This last exposure time made the sharp star at the end of each trail.
I had no watch or stopwatch handy, so I had to count the 40 seconds in my mind: One, two,... Therefore all times are estimated times only.
This technique shows the constellation as well as the star colors.
Stefan Seip
|