Anywhere Is: The Another Sky
featuring the constellation of the Southern Cross, the Jewel Box cluster (NGC4755), the Carina Nebula (NGC3372), the part of the Coalsack globule, a good load of star clusters and nearly 27 megapixels of stars, dust, hydrogen and dark matter ;)
Chance of getting any image of Southern sky during my trip to Tanzania was pretty low - rainy season was on the way, the Moon was pumping itself up to its full power and getting out of the building at night in the middle of a national park full of lions and (even worse!) buffalos was just too scary (Tanzanian regulations forbid fences around lodges).
But one day before departing back home my dice had rolled six :)
17.04.2014 provided great conditions - good weather (no clouds, no haze, rain was in the morning), about an hour of nice Southern darkness between the beginning of astronomical night (Sun below -18°) and the rise of the Moon, and relatively dark (if compared to mainland Tanzania where night are just pitch black), comfortable open place on the North-Eastern shores of Unguja island (lion/buffalo/leopard etc.-free area :) with largely unobscured Southern horizon.
Using Polarie @6° South is quite a unique experience. The alignment is a minor issue if compared to the problem of how to point the camera at the desired area of the sky? My setup ended with awkward "backbend" position with shutter relize button and flash hot-shoe facing the Earth. So to use the finder I had to crawl between the tripod legs. Not an option! I didn't use a finder and had a tough time framing :)
Aquisition time (start of a session): JD 2456765.18333333 (17.04.2014 19:24:00 local time in Tanzania)
Image orientation: straight.
Canon EOS 60D (unmodded) with Canon EF-S 60 mm f/2.8 macro USM lens on Vixen Polarie star tracker mounted on photo-tripod via Manfrotto 410 Junior geared head.
Aperture 21,5 mm
Focal length 60 mm
Tv = 35 seconds
Av = f/2,8
Exposures: 27+14+19 (plus 22 dark frames, plus pre-made master bias and master flat-field from the library)
Processing: images were converted into Adobe .DNG with Abode converter, stacked in DSS.
Final touches were made in Photoshp, namely
1) Levels=>gamma 2,75;
At this point panels were stitched together in Microsoft ICE
2) Levels => zero for all channels set at the left margin of respective background peak;
3) Curves => badly asymmetric sigma-shaped curve was applied.
4) finally gamma was raised to 1,2.