Filter automation

21:06 12/2/2010 UTC

Long cloudy period usually means shopping instead of imaging... I've used manual filter pocket for a while now and saw some real andvantages using an automated solution. Changing filters manually practically ment I had to shoot long series with one filter at a time. Using filter wheel I can sequence one shot per filter and loop the sequence throughout the night. My choice was Starlight Xpress USB Filter Wheel. It is an USB powered very nice piece of hardware, which works like a charm. Filter change is quiet, fast and seems to be quite accurate. I have to confirm the accuracy after shooting some flats. Only downsides are a bit thin software support and a little thick construction (29mm). There's no ASCOM drivers nor Nebulosity support, at least yet. MAC OS has already a Nebulosity support in place, so I hope it's just a matter of time when we see Windows support also. Thinkness prevents me from using this wheel with Canon EF lenses. Wheel and camera together (29+18mm) is more than the back focus requirement of Canon lenses. Now if the skies would clear up - and without -20C temperatures please...

The California Nebula project continues

17:36 22/11/2009 UTC

Finally after almost a month sky cleared again and what a night! SQM gave almost record readings for my site and sky was pitch black without moonlight. OIII is sensitive to moonlight, so this was the time to shoot it for my California Nebula project. There was quite a nice set of data and I managed to catch some of the elusive OIII emission and even hints of some features in it.

NGC/IC Object List:
NGC1499 gaseous nebula RA:04h03m14.4 Dec:+36°21m'33" BMag: 5.0, LBN 756 California Nebula

Camera: Atik Instruments 4000LE | Telescope: Skywatcher ED80 Pro 80mm f7.5 refractor, William Optics 0.8x focal reducer | Mount: Vixen GP-D2, Boxdoerfer PowerFlex MTS-3SLP drive controller | Filters: Baader H-alpha 7nm 2", Baader OIII 8.5nm 2" | Guiding: The Imaging Source DMK 21AU04.AS CCD camera, Orion ShortTube 80mm f5 refractor, Stark-Labs PHD Guiding | Exposure: Ha 10x900s (2h30m) unbinned, CCD @ -30° f6, OIII 16x900s (4h) unbinned, CCD @ -30° f6 | Software: CCDWare CCDStack, Adobe Photoshop CS4, Stark-Labs Nebulosity 2 | Location: 60°31'N 26°52'E (Koivula/Kotka,FI) | Background sky brightness (SQM): 20.10 mag/arcsec² | Target altitude in the beginning of the exposure 41°

The California Nebula

20:10 29/10/2009 UTC

After a long cloudy and rainy period we finally got some nice weather (and moon of course). I had tuned my mount for few nights and had to shoot something to test it. California Nebula came in mind first, so it aimed at it. To proof my mount working as expected I did 15min subs and it worked fantastic. Too bad I forgot to switch dithering on. All in all, I got quite a nice set of data. Man, it is a HUGE object! Maybe I have to try to dig out some SII and OIII too for this.

NGC/IC Object List:
NGC1499 gaseous nebula RA:04h03m14.4 Dec:+36°21m'33" BMag: 5.0, LBN 756 California Nebula

Camera: Atik Instruments 4000LE | Telescope: Skywatcher ED80 Pro 80mm f7.5 refractor, William Optics 0.8x focal reducer | Mount: Vixen GP-D2, Boxdoerfer PowerFlex MTS-3SLP drive controller | Filters: Baader H-alpha 7nm 2" | Guiding: The Imaging Source DMK 21AU04.AS CCD camera, Orion ShortTube 80mm f5 refractor, Stark-Labs PHD Guiding | Exposure: Ha 10x900s (2h30m) unbinned, CCD @ -30° f6 | Software: CCDWare CCDStack, Adobe Photoshop CS4, Stark-Labs Nebulosity 2 | Location: 60°31'N 26°52'E (Koivula/Kotka,FI) | Background sky brightness (SQM): 18.85 mag/arcsec² | Target altitude in the beginning of the exposure 48°

Learning image processing

07:18 23/10/2009 UTC

I first learned about a this new processing technique back in ATM meet in Artjärvi. J-P Metsävainio gave a very quick presentation on his Tone Mapping technique, which is very well suited for Narrowband work. While processing my Heart Nebula image I decided to give J-P's method a try. I instantly realised it potential and some pitfalls also. First, I learned there is nothing you can get to the image what already isn't there. So good SNR here is very essential, as always. As soon as you have a good raw data, the results are fantastic. The example image shown here has split in two, one side with my previous way of processing, the other using Tone Mapping. With this technique you get clean colors, good control over the color balance and the best: Absolutely zero purple halos around the bright stars! You can find a presentation of J-P's technique in his homepage .

Milky Way over Arezzo

19:02 17/9/2009 UTC

Greetings from Italy! I've always kept imaging Milky Way a difficult challenge. To get a perfect image, one needs a very dark and clear sky, sharp and fast optics and preferrably a nice scenery. I didn't have any tracking mount with me, but actually didn't even need one. Sky limit was easily reached with 20s subs due to quite heavy light pollution from the city of Arezzo. Clouds were passing by and also caused some bloats in the parts of the image. I have removed the brightly lit blurred trees from the front to make the image more pleasant to view. The best memory from this image is the conditions it was taken in. I was wearing no shoes nor socks and had only shorts and T-shirt on. Luxury we don't have here up north...