Southern Pinwheel Galaxy – M83 or NGC 5236, 30 x 300s
Omega Centauri – NGC 5139, 24 x 90s
NGC 6726, 6727, 6729, IC 4812 in Corona Australis
NGC 6188, 24 x 300s
IC 4603 and Rho Ophiuchi, 16 x 300s
Centaurus A – NGC 5128, 25 x 300s
Cat’s Paw Nebula – NGC 6334, 16 x 300s
IAS Observatory, Hakos, Namibia
20″ Philipp Keller Cassegrain primary focus @ 1500mm f/3
Liebscher Mount with FS2
Off axis guiding with Lodestar X2, dithering with BackyardEOS and PHD2
Canon 5D Mark II (a) or 5D Mark III (unmod), varying crop
Varying # of subs and exposure, see above, ISO 800 + sky flats/bias, no darks
Image processing DeepSkyStacker, Lightroom, Photoshop
Time-lapse video from a short trip to the IAS Observatory (Internationale Amateur Sternwarte) at Hakos, Namibia in June 2014.
Natürlich darf auch ein Zeitraffervideo von der Internationalen Amateursternwarte IAS auf Hakos, Namibia nicht fehlen. Und so pittoresk die Wolken hier auch sind, in drei von acht Beobachtungsnächten waren sie dann doch störend. Insbesondere für Michael und Lutz, die eine Sternbedeckung durch den Asteroiden Chariklo bzw. dessen Ringen vermessen wollten.
Video erstellt mit Lightroom, Starstax, Avisynth, VIrtualdub, Handbrake. Schön, dass einige freie “Old School” Werkzeuge für die Videoverarbeitung da noch mal richtig nützlich sind.
Hier im Blog ist es noch nicht so in Erscheinung getreten, aber wer meine Aktivitäten auf Facebook, Twitter, Google+ und ipernity verfolgt, wird es schon gemerkt haben: seit Herbst letzten Jahres hat mich das Thema Astrofotografie gepackt.
Sogar so sehr, dass ich doch glatt im Juni mit Michael nach Namibia geflogen bin, um einen wirklich dunklen Sternen(süd)himmel zu erleben. Was wiederum so begeisternd war, dass ich jetzt auch Mitglied bei der Internationalen Amateursternwarte (IAS) geworden bin, die auf der Hakos-Farm und dem Gamsberg eine fantastische astronomische Infrastruktur bietet.
Wie will man es beschreiben? In weiten Teilen Europas haben wir den dunklen Sternenhimmel zu einem hell zubetonierten Garten gemacht. Nur hier und da schauen ein größerer Baum oder Strauch raus. In Namibia sieht man den kompletten Garten mit noch den kleinsten Blumen.
Allerdings haben wir dort auch Lichtverschmutzung feststellen müssen. Morgens vor Beginn der astronomischen Dämmerung war das Zodiakallicht doch ganz schön hell und störend. ;-)
The relatively dark skies and several clear nights on Rügen’s “Muttland” during our recent Berlin-Rügen-Wismar trip had to be portrayed as a star trail, of course. With the new fisheye toy, the camera was just lying on its back on a small table in the hotel garden while we were stargazing. ;-) Result ist the image above, compiled from 264 single exposures at f/4, ISO 400, 30 s (in reality approx. 32 s) for a total time of 8630 s.
Combining the images can be done with a variety of tools. Photoshop or other image manipulation tools, and the “lighten” layer mode being somewhat obvious, but 264 layers with 21 Mpxl would certainly stress resources heavily. So there are some specialists out there: StarStaX and Startrails, both Windows programs offering a “lighten” and a “gap filling” mode among others.
For the circular fisheye here “gap filling” is not really required. Nevertheless the result shown above is from StarStaX in “gap filling” mode, as I like StarStaX’s slight increase in local contrast compared to “lighten”. When stacking images in “lighten” mode, both programs will output absolutely identical results. In “gap filling”, I found that Startrails yielded a too bright background for the image series. All in all I tend to prefer StarStaX, even if “comet mode” in StarStaX wasn’t that much of a success.
Neither StarStaX nor Startrails handle embedded meta data, so some postprocessing with exiftool is required:
An alternative is to use ImageMagick, the command line tool convert can do the “lighten” stacking as follows:
convert INPUT*.jpg -evaluate-sequence max OUTPUT.jpg
For the stacking, the image series needs to be exported from Lightroom first, JPEGs at max quality are sufficient. StarStaX supports 16 bit TIFFs on input, but not for output. Make sure to check the “Write Keywords as Lightroom Hierarchy” setting, the exiftool command above ensures that the “flat” keywords don’t mess up the keyword hierarchy during import.
One big caveat, and I found this out the hard way: in preparing the image series for export from Lightroom, don’t apply any development settings which change the geometry of the image, e.g. crop with rotation or lens distortion correction! Doing so will result in banding-like artefacts in the stacked result!
TSE 13/14 Nov 2012 Australia – Revised Corona Composite v1
Equipment, what worked, what didn’t? Well, everything did, so I’m quite happy with the setup used to photograph the 13/14 Nov 2012 total solar eclipse:
When using EclipseOrchestrator, it is extremely important to test the control scripts thoroughly, over and over again. Camera cycle times and overall timing are tricky, especially when using mirror lockup and a serial port shutter cable. BTW: Fred’s support for his program is superb!
The Astrotrac’s tracking time is approx. 2 hours, not completely a perfect match for a total solar eclipse. And you definitely need something like the wedge and GIRO-mini, a normal “photo” ball head just won’t do it. For this eclipse the GIRO-mini would probably have worked without counterweights, as the sun was just 12 degrees above the horizon at totality and thus the GIRO-mini in a more or less upright position.
