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Showing results for tags 'debayering'.
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Hello guys and girls, these are the first adventures of a new CCD user. I hope you'll have a bit to laugh i bought a used QHY8 from a fellow stargazer. It arrived yesterday. It was missing the documentation (but in the documentation was not part of the deal, so that's okay). After quite a while I got everything running (the Camara needs two power sources). As the weather was good for the first time in years, I immediately set up in my garden at 11 PM. First I was struck by a faulty USB cable - it took me about an hour and a half to isolate the problem as it was not constantly failing but intermittantly freezing the software and/or windows. But after that, i was able to shoot a few short moon sequences with APT. However, the result was less than optimal. I was getting pesky little black squares. I suspected something with debayering and asked APT's Ivo and the qhyccd forum for help. Ivo answered within about 30 mins, and after 2 or 3 messages everything was clear: the debayering settings in APT refer only to the display within APT, not to the saved images ! (I hear the more experienced SGLers ROFLing) After some updates and mouseclicks, i got nice little stacked images of the full moon. The next problem was the cooling: the unit cooled very well when connected straight to a power source, but with the QHY power converter in-between the cooling was mediocre (guessing from the outside temp of the casing). Also, the unit stubbornly said it was running at 25C, but the pictures were ok (yes, i know, moon pics dont have to worry about SNR, but still, they were ok, some test darks at 30 secs were also very ok). Well, to cut a long story short: the QHY8 does not have a temp sensor!!! Its supposed to cool straight away at max power. APT (and other software) is somehow getting wrong temp values. Finally, i used the QHY power converter for the sony chip and a second power supply for the cooling. The finding: the cooling via the QHY power converter was much weaker- even the fan went at a little lower rotation speed. Running through the second power supply, the unit cooled great. Possibly one of the cables was mistakenly sent instead of the original one- it looks suspiciously thin for a cable that is supposed to be transferring 36 watts at 12 volt. So, after several hours of silently swearing, everything works! Yay!!! PS: the suspiciously thin 36 watts cable (the cross diameter of the plug is 2.5mm):
Hi, I normally using the AstroImageJ software when doing the first steps in my preparing of astrophotos. My camera is a Canon EOS 6D, it has a normal singel color sensor with Bayer pattern filter. There are a lot of different Bayerpattern, Canon normally has the filter order RGGB. In my case I read out the overscan region of sensor and then maybe the start pixel position can be at another color filter. Sometimes I feel it's a bit hard to bring out the color in the following steps. So I had to test that I didn't mixed up the Bayer pattern when I created the macro that do the demosaicing. To test this I made a RGB color test pattern image and took photos of it. Then demosaicing the CFA image to get 4 new images Red, Green1, Grenn2 and Blue, each 1/4 of the original size. From these images I easy see if the demosaicing is done correct. If it's interesting read about more details I have put together a page over what I do when testing the demosaicing function: http://www.astrofriend.eu/astronomy/tutorials/tutorial-raw-demosaic-combine/tutorial-raw-demosaic-combine.html What result did I get? It was correct so I don't have to worry about that as long I keep my Canon camera. /Lars